3 What does the fact that the brain has been shaped through natural evolution imply as to knowledge and thought?

The evolutionary process, as many now agree, follows a pragmatistic pathway, in which each step is generated through a non-oriented mechanism, and accepted or rejected according to a criterion of relative advantage, not of perfection. Acceptance of a step is conditioned by what has been built by the previous ones.

This determines the occurrence in nature of multiple pathways, each linked to a particular organismic architecture, in which solutions to similar problems can largely differ. For instance, flight has been achieved by the unrelated wings of insects and birds, vision by eyes so varied as those of flies and octopuses, or men.

Such a claim, which is generally well accepted for motor or sensory functions, should be extended to the higher domains of knowledge and thought in general. The indication of their relative, instrumental character would consequently be supported; they would appear to represent a particular arrangement, among many possible ones, functional to the demands facing the humans - and not necessarily the best for other systems, including artificial ones.