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Neuroethics (2025) 18:12
https://doi.org/10.1007/s12152-025-09584-7
ORIGINAL PAPER
Brain Preservation andCryonics Through theLens
ofMoral Psychology
AlexanderGerman · MaxTretter
Received: 25 March 2024 / Accepted: 16 January 2025
© The Author(s) 2025
Main
Introduction
Endeavors to defy death, like attempted resurrection,
the quest for immortality, and related endeavors to
defy the perceived natural order, often are caution-
ary tales, and such narratives extend from ancient
mythology to modern popular culture. Orpheus, the
mythic musician, unable to accept the death of his
beloved Eurydice, attempts to rescue her from the
Underworld, but fails and dies a violent death him-
self. In the Mesopotamian Epic of Gilgamesh, the
quest for immortality turns out to be futile. The iconic
Mephistolian bargain in Goethe’s Faust highlights the
perils of selling one’s soul. Rather than restoring life
in its entirety, modern zombies symbolize a partial,
often grotesque, form of resurrection. Lord Volde-
mort’s Horcruxes in “Harry Potter” are a most sinister
attempt at immortality because their creation requires
committing a murder. In the digital age, the “Tran-
scendence” movie portrays catastrophic outcomes of
mind uploading after death. Deep-seated human anxi-
eties and desires might contribute to the suitability of
the endeavor to defy death as a literary material.
As science advances, cryonics emerges as a bridge
to potential real-world implementation of these deep-
seated desires. The basic idea of cryonics, i.e., post-
mortal preservation to enable this-worldly revival,
has been documented in a letter by Benjamin Franklin
as early as 1773 [1], but the cryonics movement has
Abstract Structural brain preservation (SBP) and
classical cryonics are techniques aimed at preserv-
ing the human brain for potential future applications.
Reluctant public discourse around these techniques
may be explained with intuitive aversions identified
by moral psychology. In the first part of the paper,
we conjecture the existence of a self-sustaining
cycle of moral condemnation of SBP and classical
cryonics due to quick, affect-laden moral intuitions.
In the second part, we propose an alternative fram-
ing of SBP and classical cryonics through a thought
experiment featuring a time machine metaphor called
"Schrödinger’s chrono-cat", which might avoid trig-
gering aversive moral intuitions and foster public dis-
course. We discuss the limitations of this framing and
its consequences.
Keywords Brain preservation· Cryonics· Moral
psychology· Dual-process theory· Disgust· Purity·
Mortality salience effects· Smart heuristics
A.German(*)
Department ofMolecular Neurology, University Hospital
Erlangen, Friedrich-Alexander-Universität Erlangen-
Nürnberg, Erlangen, Germany
e-mail: alex.german@fau.de
M.Tretter
Department ofSystematic Theology, Friedrich-Alexander-
Universität Erlangen-Nürnberg, Erlangen, Germany
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only gained momentum after a 1962 book written by
its founder, Robert Ettinger [2]. While there has been
some criticism of cryonics [3], since 2009, several
papers in mainstream bioethical journals have argued
that cryonics is morally permissible [4, 5]. In 2020,
Thau went one step further and even argued that
cryonics is morally obligatory [6]. Despite a signifi-
cant number of bioethical papers, books and essays
have argued for the basic idea of cryonics [1–17], it
remains a niche phenomenon [18].
In this paper, we do not aim to add to the argu-
ments on cryonics, nor argue for its precedence over
other important areas of research. Instead, we will
analyze obstacles when discussing these arguments in
the general public. We rely on a current understand-
ing of moral psychology, which emphasizes the bio-
logical basis of morality over formal reasoning. In
particular, we will.
Part 1. Identify mechanisms of morality which
obscure the arguments for cryonics and help to
explain the reluctant discussion of cryonics.
Part 2.Propose to frame cryonics as a metaphori-
cal thought experiment which might bypass these
mechanisms and enable discussions in the general
public.
The identification of obscuring mechanisms of
morality will motivate our metaphorical thought
experiment. We primarily intend to defend the perti-
nency of our thought experiment and will only deal
with objections related to moral intuitions. We will
outline limits to the normative consequences of our
analysis.
Part 1
Defining Death
To anchor discussions of cryonics, it is helpful to
distinguish between different criteria for death.
According to the 1981 US Uniform Determination
of Death Act (UDDA): “An individual who has sus-
tained either (1) irreversible cessation of circulatory
and respiratory functions, or (2) irreversible cessa-
tion of all functions of the entire brain, including the
brain stem, is dead. A determination of death must
be made in accordance with accepted medical stand-
ards.” The UDDA is not without contention, and nei-
ther are the “accepted standards” for determining that
the cardiorespiratory criterion (1) or the whole-brain
criterion (2) are met [19–25]. In the context of cry-
onics, an alternative information-theoretic criterion
for death has been introduced by Merkle in 1992 [9].
This criterion has remained well outside “accepted
standards”, but has been quoted frequently, e.g., by
Moen [5]:
“If we knew the coordinates of each and every
atom in a person’s brain then we would (at least in
principle) be in a position to determine with absolute
finality whether their memories and personality had
been destroyed in the information theoretic sense, or
whether they were preserved but could not, for some
reason, be expressed. […] If the structures in the
brain that encode memory and personality have been
so disrupted that it is no longer possible in princi-
ple to recover them, then the person is dead. If they
are sufficiently intact that inference of the state of
memory and personality are feasible in principle, and
therefore restoration to an appropriate functional state
is likewise feasible in principle, then the person is not
dead. A simple example is in order. If a computer is
fully functional, then its memory and ‘personality’
are completely intact. If we took an axe to the CPU,
then the computer would no longer be functional.
However, its memory and ‘personality’ would still
be present on disk, and once we repaired the CPU we
could fully restore the computer.” [9]
By requiring an atomic-level brain scan to estab-
lish that a person cannot be recovered “in principle”,
i.e., by arbitrarily advanced future technology, the
information-theoretic criterion imposes a high bar
on falsification. Due to this asymptotic nature, it can
presently only be established by complete physical
destruction of the brain, e.g., by decay or cremation
[9]. A tangible exclusionary standard, that tentatively
makes death according to the information-theoretic
criterion less likely, has emerged from connectomics
research, i.e., the comprehensive mapping of nervous
systems. This connectomic standard is identified with
the degree of structural preservation in brain speci-
mens as assessed by microscopic integrity and trace-
ability of synaptic connections and strengths [26]. A
connectomic standard has been endorsed by Seung
[27] and Hayworth [15], and implicitly follows from
statements of other connectomics researchers like
Denk, Briggman and Helmstaedter:
“Moving beyond the brain’s algorithms, connec-
tomics may ultimately allow us to read memories if,
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as many neuroscientists believe, memory is stored
in the pattern of synaptic connections and strengths.
Given that it can survive the shutdown of almost all
neural activity (the electroencephalogram is flat dur-
ing deep anaesthesia), long-term memory must cer-
tainly be encoded in the structure of the brain and
thus be readable by some form of structural analysis.”
[28]
Here, we will maintain the conventional criteria for
death as implied by the UDDA. At the same time, in
case the information-theoretic criterion is not estab-
lished, we maintain that reversibility in the future
cannot be ruled out. By reversibility in the future, we
mean that future technology might either revive pre-
served bodies or restore individuals using information
preserved in the brain structure. This pragmatism is
analogous to declaration of death in absentia, which
typically presumes death only on balance of prob-
abilities [29], and analogous to religions with a belief
in an afterlife, which still adopt the concept of death.
Defining Cryonics
Classical cryonics is a movement related to the field
of cryobiology, which started to preserve corpses
with freezing techniques in the 1960s. Today, clas-
sical cryonics employs the technique of vitrification
for preservation of whole humans, of the head, or just
– but always – of the brain, hoping that future tech-
nologies will be able to revive them [2]. To this end,
the tissue water is partially replaced with cryoprotect-
ants. Upon cooling to cryogenic temperatures, the
tissue structure is locked in a glass, preventing decay
for millennia [30]. Specimens have to be stored below
−130 °C to avoid devitrification. Functional cryo-
preservation by vitrification is an active field of basic
research, and has been successfully applied to the rat
kidney and liver [31, 32]. Functional cryopreservation
has not yet been demonstrated for the whole adult
mammalian brain, let alone body [33–40]. An indi-
vidual undergoing cryonics is therefore dead accord-
ing to the UDDA, while the information-theoretic
criterion is not established. In the cryonics terminol-
ogy, the preserved specimen is often called “patient”,
implying that the respective person is not dead [3]. If
functional cryopreservation of the whole human brain
or even body with retention of personal identity was
achieved in the future, this technique could become
applicable to living patients as a medical procedure,
making such terminology more justified [41].
Modern structural brain preservation (SBP) is
related to the field of connectomics and aims to pre-
serve the nanoscale ultrastructure of the brain [26,
27, 42]. To this end, fixatives such as the chemicals
formaldehyde and glutaraldehyde are used to harden
and stabilize the brain tissue by cross-linking all
proteins. This locks the brain structure in a gel, pre-
venting decay [43]. SBP specimens can be stored at
room temperature for centuries, due to the chemical
stability of the peptide bond [44]. Once the brain is
chemically preserved, biological functions cease irre-
versibly. An individual undergoing SBP is therefore
dead according to the UDDA, while the information-
theoretic criterion is not established. The criterion is
tentatively excluded, to the extent the connectomic
standard is met.
Proponents like Merkle speculate that “in the late
21st or twenty-second century” [9], advanced scan-
ning technologies might be able to read the preserved
brain structure entirely, enabling downstream applica-
tions like uploading an individual’s mind to a com-
puter [11], transferring it to a recreated biological
system [7], or repairing the original specimen [9].
The quality of the microscopic brain structure in
SBP is currently deemed superior to classical cryon-
ics according to the connectomic standard [45]. SBP
can be combined with vitrification, increasing dura-
bility and molecular detail of preservation [46]. For
simplicity, we use the term cryonics as a generic term
to refer to both SBP and classical cryonics, i.e., “cry-
onics = classical cryonics + SBP”, because revival is a
specific downstream application of SBP and system-
atic arguments for classical cryonics rely on its capac-
ity for SBP [9]. Some systematic technical revival-
scenarios for cryonics feature mind uploading, e.g.,
for reverting agonal damage, resulting in either per-
manent [11, 12], or transient [9] upload of the mind
to a computer. It is unclear whether the present pres-
ervation techniques will eventually lead to survival.
E.g., some philosophers doubt that mind uploading
could re-instantiate a conscious mind of moral sig-
nificance with retained personal identity [12, 47–49].
It is clear however, that the probability of survival is
higher after cryonics than after cremation. Ultimately,
the question of whether cryonics will turn out to be
feasible seems empirical, and presently eludes defi-
nite judgement.
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Thus far, only a few hundred cryonics procedures
have been carried out by a few rather small compa-
nies. No mainstream healthcare provider is known to
offer cryonics services, and no mainstream research
funding agency is known to have taken up cryonics
[18]. Moen has stated that this “is unfortunate, […]
since if cryonics is in fact technically feasible, it has
the potential to save millions of lives” [5]. A con-
structive discourse around cryonics seems important
but requires an open and unbiased examination of
the matter. Pressing topics include, e.g., regulation
on patient information, quality and confidentiality, as
well as research funding [5, 6, 50]. We will now turn
to psychological obstacles in the current framing of
cryonics that need to be addressed in order to pave
the way for a balanced discussion of cryonics in the
general public.
The Mechanisms of Morality
By classifying actions and intentions as “right” or
“wrong”, moral judgement regulates behavior within
social groups [51]. While the biological basis for
morality is complex and incompletely understood
[52], the social intuitionist model (SIM) in moral
psychology suggests that moral judgement is strongly
influenced by intuitions, colloquially known as “gut
feelings” [51]. The SIM builds upon dual-process
models of two types of cognition termed the intuitive
system and the reasoning system [53, 54]. Readers
may also be familiar with the more neutral terms “sys-
tem 1” and “system 2”, which were coined by Daniel
Kahneman in his book “Thinking fast and slow” [55].
The intuitive system is common to all mammals and
produces results in a quick, automatic, and effortless
way. The reasoning system is assumed to be unique to
humans. It is a slow and effortful, consciously acces-
sible process which is particularly suited for multistep
logical tasks. In humans, the attentional resources
required for the reasoning system are limited [53, 54].
Specifically, the SIM posits that the formation of
moral judgement starts with intuitions, and that rea-
son is harnessed post-hoc, often as a means to justify
and display one’s moral intuitions to others [51, 56,
57]. Often, humans make moral judgement based
on social interactions and the evolutionary need to
maintain a good reputation. The strong social deter-
mination of moral intuitions is hypothesized to have
an evolutionary link to human ultra-sociality, i.e., the
ability to intensively cooperate in groups of thou-
sands, in which humans are unique among mammals
[58]. In general, a strong influence of moral intuitions
on ethical reasoning can be used to explain the dif-
ficulty of persuasion in ethical discussions, consider,
e.g., abortion or assisted suicide [14, 59]. The focus
on moral intuitions as a biological basis of morality
is in opposition to the emphasis on formal reasoning
advocated by Kohlberg [51].
While direct interpersonal harms like rape, theft
and murder are considered immoral almost univer-
sally,1 moral intuition extends to concepts beyond
direct interpersonal harm and fairness, which have
often been referred to as “purity” (e.g., rituals,
taboos, and other behavioral norms, [60]). The con-
cept of “purity” varies considerably across cultures
and societies [60] and has also been used to explain
differences between conservative and liberal politi-
cal orientation [61]. It has been proposed that, start-
ing from evolutionary predispositions, moral intui-
tions are acquired from interaction with peers during
childhood, similar to language acquisition [62, 63].
Moral diversity resembles the variance of languages
between groups [51]. The operationalization of
“purity” also varies across research papers [60]. Four
distinct mechanisms for moral psychology beyond
direct interpersonal harm have been defined by Gray
et al. [60], and are called pathogen avoidance, cul-
tural assumptions, higher-order harms and signals
of cooperation. In the next section, we will describe
these four mechanisms and how they can be triggered
by cryonics.
The Mechanisms of Morality as they Pertain to
Cryonics
Cryonics procedures involve gaining surgical access
to the chest and the skull, or decapitation. Inflicting
injuries on the body of a recently deceased person
might still be perceived as direct interpersonal harm
and has been reported to be distressing for observers
[50], and cryonics could actually cause direct harm by
disrupting the mourning process of the bereaved [64].
Cryonics is also rendering those undergoing preser-
vation powerless and might expose them to risks in
1 There are important exceptions including, e.g., warfare, capi-
tal punishment, or the sati practice.
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the far future, e.g., in a dystopia, in which direct harm
could be inflicted on the preserved via experimenta-
tion [6].
In this section, we will argue that cryonics trig-
gers mechanisms for moral intuitions beyond direct
interpersonal harm. While there are no direct empiri-
cal studies of moral intuitions and cryonics, a large
empirical study conducted in 2018 has linked dif-
ferences in moral intuitions with differing attitudes
towards mind uploading [65]. As explained above,
mind uploading and cryonics overlap substantially
in terms of their assumptions and advocates. We will
now describe how cryonics can independently elicit
all four of the mechanisms of morality defined by
Gray etal. [60]:
a) Pathogen avoidance [60] is a mechanism related
to the basic emotion of disgust, inducing disease-
avoiding behavior [66, 67]. In many languages,
immoral behavior is described as “disgusting”,
and moral disgust has been linked to primitive
physical disgust reactions [68]. Disgust is used
to explain, e.g., why people moralize the contact
with the dead body [69]. It seems evident that
the involvement of corpses and brains in cryon-
ics is an elicitor of disgust [69–71]. Additionally,
cryonics could give the impression of human
corpses being treated like food: In everyday life,
preservation and freezing are techniques applied
to foods. Disgust reaction can be aggravated by
food-related contextual factors [72], and the
wording of “preservation” and “freezing” in con-
text of corpses and brains might aggravate patho-
gen disgust, although technically, modern preser-
vation techniques in cryonics employ vitrification
instead of freezing. The food context might be
avoided by using the term “archiving” instead.
b) Cultural assumptions [60] about the way in which
group members should behave are a mechanism
to ensure social cohesion [62]. It helps to explain
moral pluralism and cultural diversity of moral
positions. E.g., Brahmin Indians have a food con-
sumption norm of a son not to eat chicken shortly
after his father’s death [73, 74]. Cryonics might
conflict with the following cultural assumptions:
– The Perception of Death: In most cultures, death
is seen as a singular and irreversible event. It
marks the end of a person’s physical existence in
the world. This understanding is ingrained, e.g., in
funeral and inheritance norms. By conceptualizing
death as a continuum and the possibility for halt-
ing and reversing it, cryonics might be perceived
as a non-conformity to these norms [75, 76].
– Religious Beliefs: Many religions have specific
teachings about the afterlife, the soul, resurrec-
tion, and the sanctity of the human body. Cryon-
ics, with its ideas of reviving persons and mind
uploading, might be seen as a non-conformity to
these religious principles [77].
– Transformation of the Human Condition: Often,
transhumanist ideas like human immortality and
enhancement are associated with cryonics [2, 78],
challenging the normal human life cycle of natural
birth, aging, and death.
c) Higher-order harms [60] cause group-level dam-
age by violation of cultural assumptions, which
might result in concrete lower-order harms [79].
E.g., disrespect for divinity (blasphemy) doesn’t
cause direct interpersonal harm, but might put
the general structure of the group at risk in the
long term [80, 81]. The non-conformities of cry-
onics mentioned in (b) might be perceived as
higher-order harms. In particular, quasi-religious
descriptions of cryonics as a “path to salva-
tion” challenges conventional religious beliefs
and institutions [18, 75, 82]. Besides, cryonics
potentially limits the accrual of inheritance due
to resource allocation to cryonics and stockpiling
of reserves for a potential revival. This limitation
is independent of whether cryonics eventually
succeeds, as some cryonicists might allocate and
stockpile resources during their lifetime before
undergoing preservation. Natural birth, life and
death is advocated by bioconservative thinkers as
a necessary mechanism for societal renewal [83,
84], warning of the potential effects of human
immortality and enhancement [85].
d) Signals of cooperation/character [60] are indica-
tive whether somebody makes a reliable group
member. Atypical behavioral signals with clear
causes are especially informative as warning
signs. E.g., necrophilia is indicative of desires
beyond the normal scope and widely considered
immoral [86]. Likewise, the subscription to cry-
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onics services is highly atypical and informative
as it suggests the subscription to transhumanist
thought, the desire for immortality and enhance-
ment, and mind uploading. It should be noted that
approval of mind uploading has been empirically
linked to Machiavellian personality traits [87].
Generally, cryonics is a reminder of one’s own
mortality. Empirical studies have found that subjects
under mortality salience (i.e., being reminded of
one’s own mortality) exhibit increased prejudice and
intergroup bias [88] and switch from ethical reason-
ing to intuitive decisions when confronted with moral
dilemmas [89]. The impact of aversive intuitions from
perceived direct interpersonal harm or the mecha-
nisms (a)-(d) might be emphasized by mortality sali-
ence effects, obscuring ethical arguments [4–6].
Due to the combination of the rarity of cryonicists
among the general population with the condemnation
of cryonics according to widespread intuitions (a)-(d),
the strong social determination of moral intuitions
seems sufficient to establish a self-sustaining cycle of
moral condemnation. This might be reflected in the
skeptical depiction of cryonics in the media, inhibit-
ing a balanced public discussion [90].
Part 2
Bypassing Aversive Intuitions
Considering the strong aversive cues described in
Part 1, moral condemnation of cryonics due to quick,
affect-laden intuitions seems natural, but inhibits pub-
lic discourse. Cryonics is a rather unfamiliar concept
with little precedence in human evolution, culture
or personal experience and arguments for cryon-
ics involve multistep reasoning [7, 9]. In such cases,
the accuracy of moral intuitions has been questioned
[91, 92]. Luhmann has even suggested that “the most
pressing task of ethics is to warn against morality”
[93]. In principle, humans can come to moral judge-
ments that contradict their intuition, which is referred
to as reasoned judgement by Haidt [51]. The capac-
ity for reasoned judgement was especially found in
trained philosophers [94] and psychopaths [51], but
can hardly be expected in ordinary people. More
commonly, cognitive dissonance caused by coinci-
dent conflicting intuitions results in activation of the
reasoning system to balance the conflicting intuitions
[95, 96], which is referred to as reflective judgement
by Haidt [51].
If a less aversive framing of cryonics existed, how-
ever, it could facilitate unbiased discussions or even
the appraisal of the arguments in [4–6]. The present
analysis of aversive cues suggests that a more neutral
framing should not be a vividly described “Horcrux-
framing” of “overcoming death by opening the skull
of corpses, extracting the brain and freezing it so that
it can later be revived by transferring the soul into a
computer and immortalize and enhance it”. Instead,
we propose introducing cryonics with its telos (i.e.,
survival by time travel [4, 9]) and eschewing the
various aversive cues of its technique (i.e., the vivid
“Horcrux-framing”). We believe a time-machine-
framing of cryonics might delay and modify intui-
tions, facilitating reflective judgement in a broader set
of people [97]. To illustrate this framing, we propose
the following thought experiment (see Fig.1):
Schrödinger’s chrono-cat: A cat gets accidentally
trapped in an inescapable chamber. The chamber con-
tains nothing but a time machine device. The device
is explosive on the outside, and experimental on the
inside. The cat can either stay outside (inaction),
resulting in certain painless physical destruction, or
enter the time machine (action), resulting in unclear
outcomes. The unclear outcomes range from pain-
less physical destruction as well, over time travel to
an unknown point in the future with no possibility for
return, to completely unanticipated outcomes. Should
the cat enter the time machine?
We argue that chrono-cat is analogous to the deci-
sion between inaction and action regarding cryonics.
On the one hand, it captures the certainty of physical
destruction upon death (e.g., by decay or cremation)
in case of inaction. On the other hand, it captures the
uncertainties, powerlessness and risks in the far future
associated with performing cryonics, as the cat has
no control of its fate after entering the time machine.
Still, it is compatible with the common conception of
death as a singular event and does not require biologi-
cal, medical, or neuroscientific knowledge. It does not
include obvious moral transgressions. There are no
elicitors of pathogen disgust like corpses, brains, and
food-connotations, nor potential “purity” violations
from transferring souls or minds. There seems to be
no obvious non-conformity with cultural assumptions
or potential for derived higher-order harms implied in
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the inaction vs. action decision, including overcom-
ing death, reviving the dead, or transhumanist aspi-
rations to immortality and enhancement. Chrono-cat
is a highly exceptional situation, but both decision
options seem comparable, i.e., a decision neither in
favor of nor against entering the time machine would
be surprising as chrono-cat is only asking for a deci-
sion between low uncertainty (destruction) and high
uncertainty (time machine). Unlike real cryonics,
neither decision constitutes alerting signals of coop-
eration/character (d). Both options in chrono-cat also
seem comparable with respect to their degree of bod-
ily injury. As the trapping in Schrödinger’s chamber
happens accidentally, the framing does not introduce
additional direct interpersonal harm compared to real
cryonics. The framing as a thought experiment might
help to reduce a stress induced deliberation-to-intu-
ition bias [98] and allow more deliberative thinking
about, e.g., a decision rule that factors in future life
achievements, will to live, and risk appetite at the
unknown point of death.
We chose to feature a cat in our thought experi-
ment for several reasons: Firstly, the cat is a direct
reference to the simultaneity in Schrödinger’s meta-
phorical thought experiment, which illustrates the
concept of quantum superposition, where a cat in a
sealed box is simultaneously alive and dead until it
is observed [99]. Superposition loosely resembles
the blurred state of individuals undergoing cryon-
ics, in whom the information-theoretic criterion
for death has not been established and who are
therefore neither alive nor certainly irrevocably
dead pending further scientific progress. Uncer-
tainty and simultaneity, “where what something is
now can only be determined later” [59], have been
related to quantum physics by other bioethicists as
“Schrödinger’s fetus” in the context of abortion [59,
100]. Secondly, we believe using a cat helps to more
realistically convey the degree of uncertainty asso-
ciated with cryonics. Time machines for humans are
a familiar theme in popular culture to tell exciting
stories, like the classic by H. G. Wells [101]. These
time machines typically work, while the uncertainty
of cryonics is higher. By contrast, feline models
have been employed, e.g., in lethal neuroscience
experiments [102]. In Schrödinger’s original hypo-
thetical experiment, the survival probability is 50%,
emphasizing uncertainty. Thirdly, superstition per-
taining to cats is widespread – e.g., cat reincarnation
has been perpetuated by Shakespeare [103] – but
these superstitions are typically taken less seriously
compared to religious beliefs pertaining to humans.
A positive bias, further reduction of religious and
cultural assumptions and mortality salience effects
might be achieved by using a non-human character.
Schrödinger’s chrono-cat reflects opt-in cryonics
(see Fig.1). The following potential modifications
of the regulatory situation regarding cryonics can
be projected:
Fig. 1 Schrödinger’s
chrono-cat
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– opt-out cryonics: The agent starts in the time
machine, and the action and inaction options
become inverted (Fig.2 A).
– compulsory cryonics as proposed by Thau [6]:
The agent starts in the time machine, and the door
is locked (Fig.2 B).
– illegal cryonics: The agent starts outside the time
machine, and the door is locked (Fig.2 C).
– expensive cryonics: The agent starts outside the
time machine, and the door can only be opened
with a fee (Fig.2 D).
Adaptations of chrono-cat to frame the failure of
a healthcare provider to offer cryonics services as a
denial of assistance are conceivable, as well as adap-
tations to cryothanasia, i.e., euthanasia combined
with cryonics to optimize preservation quality [8,
14]. Furthermore, social aspects of cryonics could be
incorporated by additional agents [50, 64].
Among the many aspects of cryonics which war-
rant a balanced public discussion, possibly using
chrono-cat, we wish to highlight the question: Can
cryonics qualify as a treatment? An intuitive guide
to shape public policy in medicine is the treatment-
enhancement distinction, which states that pub-
lic resources should be directed to treatments, i.e.,
interventions that maintain or restore health [104,
105]. From its start, cryonics has been conceptual-
ized as an enhancement aiming at radical life exten-
sion or “immortality” [2, 3], see also Thau [6].
However, if successful, we are wondering if cryon-
ics could simply serve as an intervention that pre-
vents millions of cases of premature death.
Fig. 2 Variations of Schrödinger’s chrono-cat for opt-out (A), compulsory (B), illegal (C), and expensive (D) cryonics
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Limitations
Schrödinger’s chrono-cat is a selective narrative and
must be combined with clear communication of the
actual nature of cryonics to avoid deception. This is
especially true when informing vulnerable patients.
A time machine metaphor might exaggerate the prob-
ability of success due to sensationalism. The attempt
of reducing aversive intuitions might be perceived as
a gaslighting strategy, i.e., disqualifying them as “too
sensitive” [106].
Chrono-cat removes triggers for mechanisms of
morality of cryonics but translocates aversive triggers
from the specific options of a decision to an increased
artificiality of the entire situation. This translocation
comes at the cost of additional aversive cues of direct
interpersonal harm and threat of the situation like iso-
lation in the chamber and the intimidation of a sudden
death. Empirical investigations of the present argu-
ments and of the majority appeal of chrono-cat are
needed. This should include influence factors on the
chrono-cat decision, invariance with respect to opt-in
vs. opt-out starting position, and intuitions related to
illegal vs. compulsory cryonics.
Another shortcoming is the representation of
cost: On the one hand, chrono-cat is hiding the cost
of classical cryonics of approximately $200,000 per
procedure [18]. On the other hand, a single-use time
machine seems disproportionately costly compared
to SBP, which is currently offered free of charge
within the framework of institutional brain banking.
Cryonics can rely on reusable equipment, as hygienic
and legal requirements for postmortem dissections
are easier to meet compared to in-vivo medical
procedures.
Chrono-cat is accurately representing the irrevers-
ibility of inaction, but it is as well describing a “fire-
and-forget” situation with irreversibility of action.
In actuality, society can decide to convert from the
action to the inaction option by destroying cryonics
specimen post hoc, allowing reversibility.
Emphasizing the role of intuitions in moral judge-
ment is not without criticism. There are deviating
positions which emphasize that moral intuitions are
shaped by prior reasoning [107, 108], get overrid-
den by emotion reappraisal [109], or transfer judge-
ment to a distributed moral debate which is led by
experts [110]. Others have criticized the dichotomy
between intuition and reason of dual-process models
altogether, arguing either for a single-process model
[111], or calling for the development of dynamic,
biologically realistic models of moral cognition [52].
Furthermore, these criticisms highlight that behavior
in hypothetical thought experiments can contradict
behavior in real-world scenarios [52, 112]. If chrono-
cat has actual effects on moral cognition on cryonics
is, therefore, up for empirical exploration.
Several philosophers and psychologists recom-
mend to improve moral judgement by avoiding moral
intuitions [91–93], while others reject the normative
significance of moral psychology [113]. In general,
the instrumentalization of the science of morality
in moral debates results in meta-normativity prob-
lems with circularity [93, 114, 115]. This normative
grounding problem has become symptomatic before,
e.g., in the specific debate if intuitive disgust reac-
tions constitute a legitimate argument in bioethics as
the “wisdom of repugnance” against human cloning,
which was put forward by Kass [83, 84] and opposed,
e.g., by Nussbaum [116]. It should be noted that the
qualification of cryonics as higher-order harms for
moral intuitions (c) does not rule out actual higher-
order harms due to cryonics, which would be con-
cealed in chrono-cat. Researchers of smart heuristics
like Gigerenzer identified situations in which intui-
tion consistently outperforms reason, even recom-
mending to base moral decisions on the intuitive
system alone, because they are informationally too
rich for the reasoning system [117, 118]. Due to this
diversity of conclusions, direct normative implica-
tions of the science of morality in the narrow sense
for goal selection, i.e., as a “policy maker”, are lim-
ited [113, 114]. Nevertheless, the science of morality
has practical implications for goal realization, i.e., as
a “choice architect” as proposed by Thaler and col-
leagues [119]. This holds regardless of the normative
significance of mechanisms of morality, dual-process
theory, and smart heuristics.
Conclusion
We have described aversive intuitions with respect
to cryonics and offered a possible bypass using
Schrödinger’s chrono-cat. This thought experiment
has implications for ways to realize discussions about
cryonics or persuasion for mainstream adoption of
cryonics, if one selects these as worthwhile goals. In
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Neuroethics (2025) 18:12
12 Page 10 of 14
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addition, chrono-cat might have scientific applica-
tions in studying moral judgement of cryonics with-
out initial aversive intuitions in empirical surveys.
We hope that awareness of moral intuitions brings
attention to the full spectrum of arguments on cry-
onics when communicating it to people from a wide
range of literary, cultural, religious, and generational
backgrounds.
Acknowledgements We are grateful for helpful comments
from two anonymous reviewersand Ramy Abdin, Karl-Heinz
Leven, Stephan Graßmann, Tabea Ott, Laeschkir Würth-
ner,Cassandra Flügel-Koch, Moritz Zaiss, Frederik Laun, Ste-
fan Rampp, Aron Koller, Jan Dobert, Marie Andert, Kristina
Battis, Fanni Boros, Rebecca Masanetz, Yanni Schneider, Pat-
rick Süß, Martin Regensburger, Jürgen Winkler, and the mem-
bers of Rösttrommel e.V.. The views expressed herein are those
of the authors alone.This work was supported by the German
Society of Cryobanks (GDK e.V.), German Research Founda-
tion grants (SFB 1483, FOR 5534) and the Interdisciplinary
Center for Clinical Research Erlangen (project J111).
Funding Open Access funding enabled and organized by
Projekt DEAL.
Declaration
Competing Interests None declared.
Open Access This article is licensed under a Creative Com-
mons Attribution 4.0 International License, which permits
use, sharing, adaptation, distribution and reproduction in any
medium or format, as long as you give appropriate credit to the
original author(s) and the source, provide a link to the Crea-
tive Commons licence, and indicate if changes were made. The
images or other third party material in this article are included
in the article’s Creative Commons licence, unless indicated
otherwise in a credit line to the material. If material is not
included in the article’s Creative Commons licence and your
intended use is not permitted by statutory regulation or exceeds
the permitted use, you will need to obtain permission directly
from the copyright holder. To view a copy of this licence, visit
http://creativecommons.org/licenses/by/4.0/.
References
1. Labaree, Leonard W. and Bells, Whitfield J. 1956. Mr.
Franklin: a selection from his personal letters. New
Haven: Yale University Press.
2. Ettinger, Robert C. W. 1964. The Prospect of Immortal-
ity. New York: Doubleday.
3. Minerva, Francesca. 2018. The Ethics of Cryonics: Is It
Immoral to Be Immortal?. Cham, Switzerland: Palgrave
Pivot.
4. Shaw, David. 2009. Cryoethics: Seeking life after death.
Bioethics 23: 515–521. https:// doi. org/ 10. 1111/j. 1467-
8519. 2009. 01760.x.
5. Moen, Ole Martin. 2015. The case for cryonics. Journal
of Medical Ethics 41: 677–681. https:// doi. org/ 10. 1136/
medet hics- 2015- 102715.
6. Thau, Tena. 2020. Cryonics for all? Bioethics 34: 638–
644. https:// doi. org/ 10. 1111/ bioe. 12710.
7. Olson, Charles B. 1988. A possible cure for death. Medi-
cal Hypotheses 26: 77–84. https:// doi. org/ 10. 1016/ 0306-
9877(88) 90118-1.
8. Minerva, Francesca, and Anders Sandberg. 2017. Eutha-
nasia and cryothanasia. Bioethics 31: 526–533. https://
doi. org/ 10. 1111/ bioe. 12368.
9. Merkle, Ralph C. 1992. The technical feasibility of cry-
onics. Medical Hypotheses 39: 6–16. https:// doi. org/ 10.
1016/ 0306- 9877(92) 90133-w.
10. Fuhr, Günther., Jochen Taupitz, Anna Zwick, and Amina
Salkic. 2013. Unterbrochenes Leben? Stuttgart, Ger-
many: Fraunhofer Verlag.
11. Cerullo, Michael A. 2016. The ethics of exponential life
extension through brain preservation. Journal of Evo-
lution and Technology 26: 94–105. https:// doi. org/ 10.
55613/ jeet. v26i1. 54.
12. Cerullo, Michael A. 2015. Uploading and branching
identity. Minds and Machines 25: 17–36. https:// doi. org/
10. 1007/ s11023- 014- 9352-8.
13. Buben, Adam. 2023. Dying to Live: Transhumanism,
cryonics, and euthanasia. In New Directions in the eth-
ics of assisted suicide and euthanasia, ed. Michael
Cholbi and Jukka Varelius, 299–313. Cham, Switzerland:
Springer.
14. Andrade, Gabriel, and Maria Campo Redondo. 2023.
Cryonics, euthanasia, and the doctrine of double effect.
Philosophy, Ethics, and Humanities in Medicine 18: 7.
https:// doi. org/ 10. 1186/ s13010- 023- 00137-5.
15. Hayworth, Kenneth. 2010. Killed by bad philosophy,
https:// www. brain prese rvati on. org/ conte nt-2/ killed- bad-
philo sophy/, Accessed 20 March 2024
16. Drexler, Eric. 1986. Engines of creation. New York:
Doubleday.
17. Freitas, Robert A., and Gregory M. Fahy. 2022. Cryosta-
sis revival: The recovery of cryonics patients through
nanomedicine. Scottsdale, Arizona: Alcor Life Extension
Foundation.
18. Stodolsky, David Sanders. 2016. The growth and decline
of cryonics. Cogent Social Sciences 2: 1167576. https://
doi. org/ 10. 1080/ 23311 886. 2016. 11675 76.
19. Nguyen, Doyen. 2020. Does the uniform determina-
tion of death act need to be revised? The Linacre Quar-
terly 87: 317–333. https:// doi. org/ 10. 1177/ 00243 63920
926018.
20. Molina-Pérez, Alberto, Bernat, James L. and Dalle Ave,
Anne. 2023. Inconsistency between the circulatory and
the brain criteria of death in the uniform determination
of death act. The Journal of Medicine and Philosophy:
A Forum for Bioethics and Philosophy of Medicine 48:
422-433. https:// doi. org/ 10. 1093/ jmp/ jhad0 29
21. Spears, William, Asim Mian, and David
Greer. 2022. Brain death: A clinical overview.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Neuroethics (2025) 18:12 Page 11 of 14 12
Vol.: (0123456789)
Journal of Intensive Care 10: 16. https:// doi. org/ 10. 1186/
s40560- 022- 00609-4.
22. Karakatsanis, K.G. 2008. ‘Brain death’: Should it be
reconsidered? Spinal Cord 46: 396–401. https:// doi. org/
10. 1038/ sj. sc. 31021 07.
23. Lewis, Ariane. 2024. The quest to revise the uniform
determination of death act: Why we tried, why we failed,
and where we go from here. Neurocritical Care 41: 339–
344. https:// doi. org/ 10. 1007/ s12028- 024- 01964-w.
24. Sarbey, Ben. 2016. Definitions of death: Brain death and
what matters in a person. Journal of Law and the Bio-
sciences 3: 743–752. https:// doi. org/ 10. 1093/ jlb/ lsw054.
25. Omelianchuk, Adam, James Bernat, Arthur Caplan,
David Greer, Christos Lazaridis, Ariane Lewis, Thad-
deus Pope, Lainie Friedman Ross, and David Magnus.
2022. Revise the uniform determination of death act to
align the law with practice through neurorespiratory cri-
teria. Neurology 98: 532–536. https:// doi. org/ 10. 1212/
wnl. 00000 00000 200024.
26. McKenzie, Andrew T., Ariel Zeleznikow-Johnston, Jor-
dan S. Sparks, Oge Nnadi, John Smart, Keith Wiley,
Michael A. Cerullo, Aschwin de Wolf, Francesca Min-
erva, Ramón Risco, George M. Church, João. P. de
Magalhães, and Emil F. Kendziorra. 2024. Structural
brain preservation: A potential bridge to future medical
technologies. Front Med Technol 6: 1400615. https:// doi.
org/ 10. 3389/ fmedt. 2024. 14006 15.
27. Seung, Sebastian. 2012. Connectome: How the brain’s
wiring makes us who we are. Boston, Massachusetts:
Houghton Mifflin Harcourt.
28. Denk, Winfried, Kevin L. Briggman, and Moritz Helm-
staedter. 2012. Structural neurobiology: Missing link
to a mechanistic understanding of neural computation.
Nature Reviews Neuroscience 13: 351–358. https:// doi.
org/ 10. 1038/ nrn31 69.
29. Jarvis, Robert M., and Megan F. Chaney. 2016. “The liv-
ing, the dead, the undecided”: An annotated bibliography
of law review articles dealing with the law of absentees
and returnees. International Journal of Legal Informa-
tion 44: 178–207. https:// doi. org/ 10. 1017/ jli. 2016. 22.
30. Fahy, Gregory M., Douglas R. MacFarlane, Charles A.
Angell, and Harold T. Meryman. 1984. Vitrification as
an approach to cryopreservation. Cryobiology 21: 407–
426. https:// doi. org/ 10. 1016/ 0011- 2240(84) 90079-8.
31. Han, Zonghu, Joseph Sushil Rao, Lakshya Gangwar,
Bat-Erdene. Namsrai, Jaqueline L. Pasek-Allen, Michael
L. Etheridge, Susan M. Wolf, Timothy L. Pruett, John
C. Bischof, and Erik B. Finger. 2023. Vitrification and
nanowarming enable long-term organ cryopreservation
and life-sustaining kidney transplantation in a rat model.
Nature Communications 14: 3407. https:// doi. org/ 10.
1038/ s41467- 023- 38824-8.
32. Sharma, Anirudh, Charles Y. Lee, Bat-Erdene E. Nam-
srai, Zonghu Han, Diane Tobolt, Joseph Sushil Rao, Zhe
Gao, Michael L. Etheridge, Michael Garwood, Marc G.
Clemens, John C. Bischof, and Erik B. Finger. 2023.
Cryopreservation of whole rat livers by vitrification and
nanowarming. Annals of Biomedical Engineering 51:
566–577. https:// doi. org/ 10. 1007/ s10439- 022- 03064-2.
33. Luyet, Basile, and Federico Gonzales. 1953. Growth of
nerve tissue after freezing in liquid nitrogen. Biodynam-
ica 7: 171–174.
34. Robbins, Richard J., Ignacio Torres-Aleman, Csaba
Leranth, Charles W. Bradberry, Ariel Y. Deutch, Susan
Welsh, Robert H. Roth, Dennis Spencer, D. Eugene. Red-
mond, and Frederick Naftolin. 1990. Cryopreservation of
human brain tissue. Experimental Neurology 107: 208–
213. https:// doi. org/ 10. 1016/ 0014- 4886(90) 90137-H.
35. Jensen, Steen, Torben Sørensen, and Jens Zimmer. 1987.
Cryopreservation of fetal rat brain tissue later used for
intracerebral transplantation. Cryobiology 24: 120–134.
https:// doi. org/ 10. 1016/ 0011- 2240(87) 90014-9.
36. Otto, Frauke, Philipp Görtz, Wiebke Fleischer, and
Mario Siebler. 2003. Cryopreserved rat cortical cells
develop functional neuronal networks on microelectrode
arrays. Journal of Neuroscience Methods 128: 173–181.
https:// doi. org/ 10. 1016/ S0165- 0270(03) 00186-9.
37. Heumüller-Klug, Sabine, Kristina Maurer, María Á
Tapia-Laliena, Carsten Sticht, Anne Christmann, Han-
dan Mörz, Rasul Khasanov, Elvira Wink, Steven Schulte,
Wolfgang Greffrath, Rolf-Detlef. Treede, Lucas M. Wes-
sel, and Karl-Herbert. Schäfer. 2023. Impact of cryo-
preservation on viability, gene expression and function of
enteric nervous system derived neurospheres. Frontiers
in Cell and Developmental Biology 11: 1196472. https://
doi. org/ 10. 3389/ fcell. 2023. 11964 72.
38. Suda, Isamu, Kyoko Kito, and Chizuko Adachi. 1966.
Viability of long term frozen cat brain invitro. Nature
212: 268–270. https:// doi. org/ 10. 1038/ 21226 8a0.
39. Suda, Isamu, Kyoko Kito, and Chizuko Adachi. 1974.
Bioelectric discharges of isolated cat brain after revival
from years of frozen storage. Brain Research 70: 527–
531. https:// doi. org/ 10. 1016/ 0006- 8993(74) 90263-7.
40. Pichugin, Yuri, Gregory M. Fahy, and Robert Morin.
2006. Cryopreservation of rat hippocampal slices by vit-
rification. Cryobiology 52: 228–240. https:// doi. org/ 10.
1016/j. cryob iol. 2005. 11. 006.
41. Bojic, Sanja, Murray, Alex, Bentley, Barry L., Spindler,
Ralf, Pawlik, Piotr, Cordeiro, José L., Bauer, Roman and
de Magalhães, João Pedro. 2021. Winter is coming: The
future of cryopreservation. BMC Biology 19: 56. https://
doi. org/ 10. 1186/ s12915- 021- 00976-8
42. Hayworth, Kenneth J., C Shan Xu, Zhiyuan Lu, Graham
W. Knott, Richard D. Fetter, Juan Carlos Tapia, Jeff W.
Lichtman, and Harald F. Hess. 2015. Ultrastructur-
ally smooth thick partitioning and volume stitching for
large-scale connectomics. Nature Methods 12: 319–322.
https:// doi. org/ 10. 1038/ nmeth. 3292.
43. McKenzie, Andrew Thomas. 2019. Glutaraldehyde: A
review of its fixative effects on nucleic acids, proteins,
lipids, and carbohydrates. OSF Preprints.https:// doi. org/
10. 31219/ osf. io/ 8zd4e.Accessed 21 Jan 2025.
44. Radzicka, Anna, and Richard Wolfenden. 1996. Rates of
uncatalyzed peptide bond hydrolysis in neutral solution
and the transition state affinities of proteases. Journal of
the American Chemical Society 118: 6105–6109. https://
doi. org/ 10. 1021/ ja954 077c.
45. 2015. Overview of 21st century medicine’s cryopreser-
vation for viability research, https:// www. brain prese rvati
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Neuroethics (2025) 18:12
12 Page 12 of 14
Vol:. (1234567890)
on. org/ 21cm- cryop reser vation- eval- page/, Accessed 20
March 2024
46. McIntyre, Robert L., and Gregory M. Fahy. 2015. Alde-
hyde-stabilized cryopreservation. Cryobiology 71: 448–
458. https:// doi. org/ 10. 1016/j. cryob iol. 2015. 09. 003.
47. Chalmers, David J. 2014. Uploading: A philosophi-
cal analysis. In Intelligence Unbound: The Future of
Uploaded and Machine Minds, ed. Russell Blackford
and Damien Broderick, 102–117. Hoboken, New Jersey:
Wiley-Blackwell.
48. Pigliucci, Massimo. 2014. Mind uploading: A philo-
sophical counter-analysis. In Intelligence Unbound: The
Future of Uploaded and Machine Minds, ed. Russell
Blackford and Damien Broderick, 102–117. Hoboken,
New Jersey: Wiley-Blackwell.
49. Cappuccio, Massimiliano Lorenzo. 2017. Mind-upload.
The ultimate challenge to the embodied mind theory.
Phenomenology and the Cognitive Sciences 16: 425–448.
https:// doi. org/ 10. 1007/ s11097- 016- 9464-0.
50 Mullock, Alexandra, and Elizabeth Chloe Romanis.
2023. Cryopreservation and current legal problems:
seeking and selling immortality. Journal of Law and
the Biosciences 10: lsad028. https:// doi. org/ 10. 1093/ jlb/
lsad0 28.
51. Haidt, Jonathan. 2001. The emotional dog and its
rational tail: A social intuitionist approach to moral
judgment. Psychological Review 108: 814–834. https://
doi. org/ 10. 1037/ 0033- 295x. 108.4. 814.
52. Bavel, Van, J. Jay, Oriel FeldmanHall, and Peter
Mende-Siedlecki. 2015. The neuroscience of moral
cognition: From dual processes to dynamic systems.
Current Opinion in Psychology 6: 167–172. https:// doi.
org/ 10. 1016/j. copsyc. 2015. 08. 009.
53. Evans, Jonathan St, and B. T. 2008. Dual-processing
accounts of reasoning, judgment, and social cognition.
Annual Review of Psychology 59: 255–278. https:// doi.
org/ 10. 1146/ annur ev. psych. 59. 103006. 093629.
54. Evans, Jonathan St B. T. 2007. Hypothetical think-
ing: Dual processes in reasoning and judgement. New
York: Psychology Press.
55. Kahneman, Daniel. 2011. Thinking, fast and slow. 1st
ed. New York: Farrar, Straus and Giroux.
56. Greene, Joshua D., Sylvia A. Morelli, Kelly Lowen-
berg, Leigh E. Nystrom, and Jonathan D. Cohen. 2008.
Cognitive load selectively interferes with utilitarian
moral judgment. Cognition 107: 1144–1154. https://
doi. org/ 10. 1016/j. cogni tion. 2007. 11. 004.
57. Greene, Joshua D. 2007. Why are VMPFC patients
more utilitarian? A dual-process theory of moral judg-
ment explains. Trends in Cognitive Sciences 11: 322–
323; author reply 323–324. https:// doi. org/ 10. 1016/j.
tics. 2007. 06. 004
58. Tomasello, Michael. 2014. The ultra-social animal.
European Journal of Social Psychology 44: 187–194.
https:// doi. org/ 10. 1002/ ejsp. 2015.
59. Räsänen, Joona. 2020. Schrödinger’s Fetus. Medicine,
Health Care and Philosophy 23: 125–130. https:// doi.
org/ 10. 1007/ s11019- 019- 09916-4.
60. Gray, Kurt, Nicholas DiMaggio, Chelsea Schein, and
Frank Kachanoff. 2023. The problem of purity in moral
psychology. Personality and Social Psychology Review
27: 272–308. https:// doi. org/ 10. 1177/ 10888 68322
11247 41.
61. Haidt, Jonathan. 2007. The new synthesis in moral psy-
chology. Science 316: 998–1002. https:// doi. org/ 10.
1126/ scien ce. 11376 51.
62. Rai, Tage Shakti, and Alan Page Fiske. 2011. Moral
psychology is relationship regulation: Moral motives
for unity, hierarchy, equality, and proportionality. Psy-
chological Review 118: 57–75. https:// doi. org/ 10. 1037/
a0021 867.
63. Haidt, Jonathan and Bjorklund, Fredrik. 2008. Social
intuitionists answer six questions about morality. In
Moral Psychology Vol. 2, ed. Walter Sinnott-Arm-
strong. Cambridge, Massachusetts: MIT Press.
64. Hillenbrink, Robin, and Christopher Simon Wareham.
2024. Mourning the frozen: Considering the relational
implications of cryonics. Journal of Medical Ethics 50:
388–391. https:// doi. org/ 10. 1136/ jme- 2023- 109237.
65. Laakasuo, Michael, Marianna Drosinou, Mika
Koverola, Anton Kunnari, Juho Halonen, Noora
Lehtonen, and Jussi Palomäki. 2018. What makes
people approve or condemn mind upload technology?
Untangling the effects of sexual disgust, purity and sci-
ence fiction familiarity. Palgrave Communications 4:
84. https:// doi. org/ 10. 1057/ s41599- 018- 0124-6.
66. Ekman, Paul. 1992. An argument for basic emotions.
Cognition and Emotion 6: 169–200. https:// doi. org/ 10.
1080/ 02699 93920 84110 68.
67. Ekman, Paul, Wallace V. Friesen, and Phoebe Ells-
worth. 1972. Emotion in the human face: Guide-lines for
research and an integration of findings. Oxford: Perga-
mon Press.
68. Chapman, H.A., and A.K. Anderson. 2013. Things rank
and gross in nature: A review and synthesis of moral dis-
gust. Psychological Bulletin 139: 300–327. https:// doi.
org/ 10. 1037/ a0030 964.
69. Tybur, Joshua M., Debra Lieberman, and Vladas Griske-
vicius. 2009. Microbes, mating, and morality: Individual
differences in three functional domains of disgust. Jour-
nal of Personality and Social Psychology 97: 103–122.
https:// doi. org/ 10. 1037/ a0015 474.
70. Oaten, Megan, Richard J. Stevenson, and Trevor I. Case.
2009. Disgust as a disease-avoidance mechanism. Psy-
chological Bulletin 135: 303–321. https:// doi. org/ 10.
1037/ a0014 823.
71. Curtis, Val, Robert Aunger, and Tamer Rabie. 2004. Evi-
dence that disgust evolved to protect from risk of disease.
Proceedings of the Biological Sciences 271 (Suppl 4):
S131-133. https:// doi. org/ 10. 1098/ rsbl. 2003. 0144.
72. Simpson, Jane, Susan H. Anthony, Stefanie Schmeer, and
Paul G. Overton. 2007. Food-related contextual factors
substantially modify the disgust response. Food Quality
and Preference 18: 183–189. https:// doi. org/ 10. 1016/j.
foodq ual. 2005. 09. 016.
73. Douglas, Mary. 1966. Purity and danger: An analysis of
concepts of pollution and taboo. Oxfordshire: Routledge.
74. Shweder, Richard A., Manamohan Mahapatra, and Joan
G. Miller. 1987. Culture and moral development. In The
emergence of morality in young children, ed. Jerome
Kagan and Sharon Lamb, 1–83. Chicago, IL, US: Uni-
versity of Chicago Press.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Neuroethics (2025) 18:12 Page 13 of 14 12
Vol.: (0123456789)
75. Mercer, Calvin, and Tracy J. Trothen. 2021. Religion and
the technological future: an introduction to biohacking,
artificial intelligence, and transhumanism. Basel, Swit-
zerland: Springer International Publishing.
76. Ahmad, Ayesha and Dein, Simon. 2022. The Death of
Cryonics: Factors Related to Its Poor Uptake. European
Journal of Theology and Philosophy 2: 1–8. https:// doi.
org/ 10. 24018/ theol ogy. 2022.2. 6. 79
77. Mercer, Calvin. 2017. Resurrection of the body and
cryonics. Religions 8: 96. https:// doi. org/ 10. 3390/ rel80
50096.
78. Ettinger, Robert C. W. 1972. Man into superman. New
York: St. Martin’s Press.
79. Janoff-Bulman, Ronnie, and Nate C. Carnes. 2013. Sur-
veying the moral landscape: Moral motives and group-
based moralities. Personality and Social Psychology
Review 17: 219–236. https:// doi. org/ 10. 1177/ 10888
68313 480274.
80. McKay, Ryan, and Harvey Whitehouse. 2015. Religion
and morality. Psychological Bulletin 141: 447–473.
https:// doi. org/ 10. 1037/ a0038 455.
81. Rowthorn, Robert. 2011. Religion, fertility and genes:
A dual inheritance model. Proceedings of the Biological
Sciences 278: 2519–2527. https:// doi. org/ 10. 1098/ rspb.
2010. 2504.
82. Dein, Simon. 2022. Cryonics: Science or Religion. Jour-
nal of Religion and Health 61: 3164–3176. https:// doi.
org/ 10. 1007/ s10943- 020- 01166-6.
83. Kass, Leon R. 2002. Life, liberty and the defense of dig-
nity: The challenge for bioethics. New York: Encounter
Books.
84. Kass, Leon R. 1997. The wisdom of repugnance. The
New Republic 216: 17–26.
85. Fukuyama, Francis. 2002. ’Our Posthuman Future’:
Biotechnology as a threat to human nature. NewYork:
fsgbooks.
86. Chakroff, Alek, and Liane Young. 2015. Harmful situa-
tions, impure people: An attribution asymmetry across
moral domains. Cognition 136: 30–37. https:// doi. org/ 10.
1016/j. cogni tion. 2014. 11. 034.
87. Laakasuo, Michael, Marko Repo, Marianna Drosinou,
Anton Berg, Anton Kunnari, Mika Koverola, Teemu
Saikkonen, Ivar R. Hannikainen, Aku Visala, and Jukka
Sundvall. 2021. The dark path to eternal life: Machiavel-
lianism predicts approval of mind upload technology.
Personality and Individual Differences 177: 110731.
https:// doi. org/ 10. 1016/j. paid. 2021. 110731.
88. Greenberg, Jeff, Tom Pyszczynski, Sheldon Solomon,
Linda Simon, and Michael Breus. 1994. Role of con-
sciousness and accessibility of death-related thoughts
in mortality salience effects. Journal of Personality and
Social Psychology 67: 627–637. https:// doi. org/ 10. 1037/
0022- 3514. 67.4. 627.
89. Trémolière, Bastien, Wim De Neys, and Jean-François.
Bonnefon. 2012. Mortality salience and morality: Think-
ing about death makes people less utilitarian. Cognition
124: 379–384. https:// doi. org/ 10. 1016/j. cogni tion. 2012.
05. 011.
90. Weaver, Courtney. 2015. Inside the weird world of cry-
onics. Financial Times. https:// www. ft. com/ conte nt/
d634e 198- a435- 11e5- 873f- 68411 a84f3 46. Accessed 21
Jan 2025.
91. Greene, Joshua D. 2014. Beyond point-and-shoot moral-
ity: Why cognitive (Neuro) science matters for ethics.
Ethics 124: 695–726. https:// doi. org/ 10. 1086/ 675875.
92. Singer, Peter. 2005. Ethics and intuitions. The Jour-
nal of Ethics 9: 331–352. https:// doi. org/ 10. 1007/
s10892- 005- 3508-y.
93. Luhmann, Niklas. 1991. Paradigm lost: On the ethical
reflection of morality: Speech on the occasion of the
award of the Hegel prize 1988. Thesis Eleven 29: 82–94.
https:// doi. org/ 10. 1177/ 07255 13691 02900 107.
94. Kuhn, Deanna. 1991. The Skills of Argument. Cam-
bridge: Cambridge University Press.
95. Stanovich, Keith E. and West, Richard F. 2000. Individ-
ual differences in reasoning: implications for the rational-
ity debate? Behavioral and Brain Sciences 23: 645–665;
discussion 665–726. https:// doi. org/ 10. 1017/ s0140 525x0
00034 35
96. Festinger, Leon. 1957. A theory of cognitive dissonance.
Redwood City, California: Stanford University Press.
97. Paxton, Joseph M., Leo Ungar, and Joshua D. Greene.
2012. Reflection and reasoning in moral judgment. Cog-
nitive Science 36: 163–177. https:// doi. org/ 10. 1111/j.
1551- 6709. 2011. 01210.x.
98. Yu, Rongjun. 2016. Stress potentiates decision biases:
A stress induced deliberation-to-intuition (SIDI) model.
Neurobiol Stress 3: 83–95. https:// doi. org/ 10. 1016/j.
ynstr. 2015. 12. 006.
99. Schrödinger, Erwin. 1935. Die gegenwärtige Situation
in der Quantenmechanik. Naturwissenschaften 23: 807–
812. https:// doi. org/ 10. 1007/ BF014 91891.
100. Milford, Stephen R., and David Shaw. 2024. schröding-
er’s fetus and relational ontology: Reconciling three con-
tradictory intuitions in abortion debates. Ethical Theory
and Moral Practice 27: 389–406. https:// doi. org/ 10.
1007/ s10677- 023- 10422-z.
101. Wells, Herbert George. 1895. The time machine. London,
England: William Heinemann.
102. Sperry, Roger Wolcott. 1959. Preservation of high-order
function in isolated somatic cortex in callosum-sectioned
cat. Journal of Neurophysiology 22: 78–87. https:// doi.
org/ 10. 1152/ jn. 1959. 22.1. 78.
103. Shakespeare, William. 1599. Romeo and Juliet. Thomas
Creede for Cuthbert Burby.
104. Daniels, Norman. 1985. Just health care. Cambridge,
England: Cambridge University Press.
105. Mehlman, Maxwell J., Jessica W. Berg, Eric T. Juengst,
and Eric Kodish. 2011. Ethical and legal issues in
enhancement research on human subjects. Cambridge
Quarterly of Healthcare Ethics 20: 30–45. https:// doi.
org/ 10. 1017/ s0963 18011 00006 05.
106. Dorpat, Theo L. 1996. Gaslighting, the double whammy,
interrogation and other methods of covert control in
psychotherapy and analysis. Lanham, Maryland: Jason
Aronson, Incorporated.
107. Pizarro, David A., and Paul Bloom. 2003. The intel-
ligence of the moral intuitions: A comment on Haidt
(2001). Psychological Review 110: 193–196. https:// doi.
org/ 10. 1037/ 0033- 295X. 110.1. 193.
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
Neuroethics (2025) 18:12
12 Page 14 of 14
Vol:. (1234567890)
108. Scherer, Klaus R. 2005. What are emotions? And how
can they be measured? Social Science Information 44:
695–729. https:// doi. org/ 10. 1177/ 05390 18405 058216.
109. Feinberg, Matthew, Robb Willer, Olga Antonenko, and
Oliver P. John. 2012. Liberating reason from the pas-
sions: Overriding intuitionist moral judgments through
emotion reappraisal. Psychological Science 23: 788–795.
https:// doi. org/ 10. 1177/ 09567 97611 434747.
110. Levy, Neil. 2006. The wisdom of the pack. Philosophical
Explorations 9: 99–103. https:// doi. org/ 10. 1080/ 13869
79050 04926 98.
111. Bluhm, Robyn. 2014. No need for alarm: A critical anal-
ysis of greene’s dual-process theory of moral decision-
making. Neuroethics 7: 299–316. https:// doi. org/ 10. 1007/
s12152- 014- 9209-0.
112. FeldmanHall, Oriel, Dean Mobbs, Davy Evans, Lucy
Hiscox, Lauren Navrady, and Tim Dalgleish. 2012. What
we say and what we do: The relationship between real
and hypothetical moral choices. Cognition 123: 434–441.
https:// doi. org/ 10. 1016/j. cogni tion. 2012. 02. 001.
113. Berker, Selim. 2009. The normative insignificance of
neuroscience. Philosophy and Public Affairs 37: 293–
329. https:// doi. org/ 10. 1111/j. 1088- 4963. 2009. 01164.x.
114. Bruni, Tommaso, Matteo Mameli, and Regina A. Rini.
2014. The science of morality and its normative impli-
cations. Neuroethics 7: 159–172. https:// doi. org/ 10. 1007/
s12152- 013- 9191-y.
115. Königs, Peter. 2018. On the normative insignificance of
neuroscience and dual-process theory. Neuroethics 11:
195–209. https:// doi. org/ 10. 1007/ s12152- 018- 9362-y.
116. Nussbaum, Martha C. 2004. Danger to human dignity:
The revival of disgust and shame in the law. The Chroni-
cle of Higher Education. https:// www. chron icle. com/ artic
le/ danger- to- human- digni ty- the- reviv al- of- disgu st- and-
shame- in- the- law/. Accessed 21 Jan 2025.
117. Gigerenzer, Gerd. 2008. Moral intuition = fast and fru-
gal heuristics? In Moral psychology, Vol 2: The cogni-
tive science of morality: Intuition and diversity, ed. Wal-
ter Sinnott-Armstrong, 1–26. Cambridge, MA, US: MIT
Press.
118. Gigerenzer, Gerd. 2010. Moral satisficing: Rethinking
moral behavior as bounded rationality. Topics in Cogni-
tive Science 2: 528–554. https:// doi. org/ 10. 1111/j. 1756-
8765. 2010. 01094.x.
119. Thaler, Richard H., Cass R. Sunstein, and John P. Balz.
2013. Choice architecture. In The behavioral foundations
of public policy, ed. Eldar Shafir, 428–439. Princeton,
New Jersey: Princeton University Press.
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