Now, if it is true that cellular and biomolecular approaches will continue to provide us with a great quantity of important information, it is likewise certain that they cannot on their own reveal to us the complexity of neural circuits or of their interactions, unveiling that is the key passageway which links the cellular and molecular neurosciences to the cognitive neurosciences. In order to understand the relationship between neural systems and complex cognitive functions it is necessary to concentrate on neural circuits, to discover how their patterns of activity interact in order to generate coherent representations, to understand how neural networks are organized and, finally, to evaluate in what way their activity is influenced by attention and by consciousness. In order to meet these objectives, biology will have to concentrate more on human beings, or on non-human primates, using brain-imaging techniques able to reveal the activity of single neurons and of individual neural networks.
In two million years the human brain has developed to the point of reaching a volume, relative to body mass, of three times the size of that of other primates. This was not only a quantitative evolution but also a cultural one, the product of a long and formidable exchange between nature and history. The brain is the foundation on which the mind rests, even if many of our most important mental faculties depend on ideas and ways of thinking that are drawn from culture and from language. On the other hand, without culture human beings could not be the moral agents that they are. Just as the free will of a human being depends on the culture and on the social system in which he/she lives, the evolution of freedom is not a natural necessity: it can also become extinct or change itself into something completely different.
A deeper understanding of our brain will lead us to re-examine our individual responsibilities, reworking fundamental political decisions and the hierarchies of social values. Emergences and functions of the human brain derive from a series of random acquisitions. In this sense the human brain did not evolve because of coherent biological functions, but rather because of reorganizations contingent upon the situation. This continuous reorganization has generated a model of hominid that is not only another evolutionary step, but a human being that gave rise to a qualitatively distinct conception of humanity and of the universe.