This book assumes that basic ways of thinking about history are hard-wired in the brain. Since different styles of discourse with which we talk about the past are hardwired, Blum infers that a protohistorical consciousness is necessary for the existence of language. Historical logics reflect some preconceived part–whole relation. Blum discerns four kinds of part-whole structure, which he terms continuity, quantum, continuum, and dialectic. Blum believes that these part–whole relations rest on universal, prereflective intuitions. He concludes that humans have different prelinguistic intuitions of time.

Blum claims that people's variable innate temporality is expressed in their historical style. It follows that historical style antedates history as a genre. Hence we are not talking about historical style, but about how individuals apply their sense of the relation between parts and wholes to the problem of time. Our study of historical context becomes secondary to the assumptions we make about the interface between part–whole relations and time. The temporality of history is derivative of a phenomenon that is not historical.

Certain conclusions are suggestive. First, modality precedes tense in evolution. Second, we ourselves are continuing to evolve. Blum believes that we are moving “towards a selection of abstract thinkers ruled by pure reason.” Instead of viewing cultures as organisms, it is more profitable to think of the evolution of structures of thinking, and to show that some are more prominent at present than they have been in the past.

For Blum, historical thinking is a dependent variable. It depends on tense and modality, which are given before language and culture. Historical thinking reflects a primary experience, but it is not such a primary experience itself.