Is rationality a cognitive faculty?

Abstract

Rationality cannot be a form of intelligence or any other cognitive faculty such as memory, language faculty, mathematical skill, and so on. To establish this thesis, this paper uses a distinction from set theory, namely, the distinction between “binary relators” and “binary operators”. Rationality acts as a binary relator in the sense that it is an optimization method, while cognitive ability acts as a binary operator in the sense that it is a transformational function. Rationality as an optimization method (binary relator) does not differ from the neo-Darwinian notion of natural selection: either method seeks to find the best choice or fit trait given the constraints. A cognitive faculty as a transformational function (binary operator) simply translates inputs into outputs. The distinction between rationality and cognitive functions has wide-ranging implications regarding the theory of evolution.