[W]hen trying to understand the character of the modern mind, it is impossible to separate the effects of genes and the developmental environment.

It is because of this notion [of species essence] that we demand that a severely brain-damaged person should have the same rights as a university professor, or a physically disabled person the same rights as an Olympian sportsman. They are all 'human', whatever their intellectual and physical abilities.

To gain an understanding of the mind leads on to an appreciation of what it means to be human.

The two centrepieces of social intelligence are the possession of extensive social knowledge about other individuals, in terms of knowing who allies and friends are, and the ability to infer the mental states of those individuals.