From animal instinct to human birth theory: an entangled path

The purpose of this paper is to analyse the discontinuity between animal and human birth. Starting from theories on animal instinct and those on animal/human behaviour; from Aristotle to Darwin, and the evolutionary synthesis of the 1940s, from distorted interpretations of Darwin's thought to some aspects of modern ethology and animal psychology, and the human birth theory, the manuscript tries to respond to the old question: what differences exist between animal behaviour and human behaviour? Trying to answer these questions, the Aristotelian scientific method and Darwin's theory of evolution are here discussed. The scientific-rational method is still not adequate to completely comprehend humankind. The main issue is the biological origin of the human psyche, the human birth theory postulated by Fagioli (2019a) several decades ago. The capability to imagine, which relates to the disappearance fantasy at human birth, is a crucial concept in the separation between humans and animals. These aspects will be thoroughly debated.