Valiant assumes that a cognitive substrate made of a few elementary functions drives the neuroidal net. When one of these functions is activated by interaction with the environment, a neural circuit is modified, and such a change contributes to successive action in the environment. A detailed computational model is worked out.
Ontological plurality is necessary to couple any theory of time with theories of other domains.
The second part of the book deals with temporal discourse. The book covers all the main formal approaches to time in a very technical and comprehensive manner. Intensional logic is useful for semantically explaining intensional contexts in natural language through multiple reference. Intensional logic provides tools such as tense, modality and conditionals. Formal descriptions are given of applications such as temporal logic and intuitionistic logic.