[Memory: a view of the history of central nervous system]

In order to stress the role and importance of memory in human nervous system, this first paper intends to show how it appeared during evolution with the cortex of brain hemispheres and how its significant growth is the cause (and not consequence) of hominization. This growth seems related to a discontinuation of the fetal period during gestation. It leads to birth before the brain is mature, substituting a genetic maturation by an epigenetic maturation through learning. This discontinuation of pregnancy is related to a purely mechanical and obstetrical cause, depending on maternal pelvis. Evolution from quadrupedia to bipedia transformed the pelvis, obliging the newborn to make his way not downward but forward, through a narrow inextensible pass. This history of memory, showing its role in human species evolution, may lead to a reflection on its role in the evolution of all the species possessing a cortex. Above all, it will allow to understand how and in which way human brain is a sort of machine totally associated with memory.