Thinking is Believing

The idea that people can entertain propositions without believing them is widespread, intuitive, and most probably false. The main goal of this essay is to argue against the claim that people can entertain a proposition without believing it. Evidence is presented demonstrating that we cannot withhold assent from any proposition we happen to consider. A model of belief fixation is then sketched and used to explain hitherto disparate, recalcitrant and somewhat mysterious psychological phenomena. The proposed model is one where beliefs are the automatic output of a computationally null belief acquisition reflex. In short, the model holds that the mere activation of a mentally represented truth apt proposition leads to immediately believing it. The essay concludes by considering some consequences that the proposed model of belief acquisition has for our concept of rationality.