Theories of Cognitive Architecture?how systems are designed so they can behave intelligently can roughly be divided into biological and computational. The computational models in turn can roughly be divided into theorem provers and networks.In this edition of Minds, Machines and knowledge we will look at the historical sources of the two kinds of computational accounts, and at a contemporary presentation of a biological account. The sources of the theorem prover account are Kant and Carnap, with some help from Bertrand Russell. We will make some comparisons with contemporary computational theories. The biological account is Patricia Churchlands.