Given the diversity of usage, a lexicographer would have difficulty in fixing a meaning. Hume defined belief as practical certainty about matters that cannot be justified theoretically. Kant looked upon belief as the subjectively adequate but objectively inadequate acceptance of something as true. In contemporary psychological literature, belief is often identified with emotional conviction. Pragmatic conceptions emphasize the operative character of conviction.
Some authors maintain that belief is relative to what the agent has at stake.
Even with the history of Western thought before us, certain key words remain ambiguous. And yet all of the authors cited have produced insights into the cognitive process, or, if you will, into the dynamics of rational assent. At different periods of history, interests are specific. Medieval discussions of belief focused upon religious belief and its relationship to empirically derived knowledge. Some of the most profound contemporary discussions of belief analyze the concept within the context of the physical sciences.