The first thing the intellect does with an object is to class it along with something else. But any object that is infinitely important to us and awakens our devotion feels to us also as if it must be sui generis and unique. Probably a crab would be filled with a sense of personal outrage if it could hear us class it without ado or apology as a crustacean, and thus dispose of it. 'I am no such thing,' it would say; 'I am MYSELF, MYSELF alone.
William JamesIf you wish to upset the law that all crows are black, you mustn't seek to show that no crows are; it is enough if you prove one single crow to be white.
William JamesTrue ideas are those that we can assimilate, validate, corroborate, and verify. False ideas are those that we cannot. That is the practical difference it makes to us to have true ideas; that therefore is the meaning of truth, for it is all that truth is known as.
William JamesMan, whatever else he may be, is primarily a practical being, whose mind is given him to aid in adapting him to this world's life
William James