Self-organisation of the economy is an old topic. But what is its nature? Is it akin to a valve which regulates a machine through a feedback loop, to the dynamic stability of a thermodynamic system, to the evolution of spontaneous order or to the self-reproduction of biological systems? In this chapter, I will introduce a particularly radical form of self-organisation. We will assume that the economy continues through a process of ongoing self-reproduction. Very much like a biological cell, the economy not only structures but generates the elements of which it consists. More precisely: the economy is defined as a network of elementary operations that recursively reproduces elementary operations.