Belief is the psychological state in which an individual holds a proposition
In logic and philosophy, the term proposition refers to either the "content" or "meaning" of a meaningful declarative sentence or the pattern of symbols, marks, or sounds that make up a meaningful declarative sentence...

 or premise
Premise can refer to:* Premise, a claim that is a reason for, or an objection against, some other claim as part of an argument...

 to be true
Truth has a variety of meanings, such as the state of being in accord with fact or reality. It can also mean having fidelity to an original or to a standard or ideal. In a common usage, it also means constancy or sincerity in action or character...

The terms belief and knowledge are used differently in philosophy.

Epistemology is the philosophical study of knowledge
Knowledge is a familiarity with someone or something unknown, which can include information, facts, descriptions, or skills acquired through experience or education. It can refer to the theoretical or practical understanding of a subject...

 and belief. The primary problem in epistemology is to understand exactly what is needed in order for us to have true knowledge.

I would rather work with five people who really believe in what they are doing rather than five hundred who can't see the point.

Patrick Dixon in Building a Better Business, p. 14

He who believes needs no explanation.

Euripides, Dionysus in "The Bacchae"

He does not believe that does not live according to his belief

Thomas Fuller, Gnomologia (1732)


Paul White

People want to believe in something-even if they know it is false.

"Tanis Half-Elven", in Dragonlance

To succeed, we must first believe that we can.

Michael Korda|Michael Korda, as quoted in Marketing Construction Services (2000) by Paul Pryor, p. 14

Nothing is so firmly believed as that which we least know.

Montaigne, Essays (1580-88)

Man is a credulous animal, and must believe something; in the absence of good ground for belief, he will be satisfied with bad ones.

Bertrand Russell, in "An Outline of Intellectual Rubbish" in Unpopular Essays (1950)

One needs something to believe in, something for which one can have whole-hearted enthusiasm. One needs to feel that one's life has meaning, that one is needed in this world.

Hannah Szenes|Hannah Szenes, in Hannah Senesh : Her Life and Diary (1938)