We [may] answer the question: "Why is snow white?" by saying, "For the same reason that soap-suds or whipped eggs are white"-in other words, instead of giving the reason for a fact, we give another example of the same fact. This offering a similar instance, instead of a reason, has often been criticised as one of the forms of logical depravity in men. But manifestly it is not a perverse act of thought, but only an incomplete one. Furnishing parallel cases is the necessary first step towards abstracting the reason imbedded in them all.
William JamesIt is so human a book that I don't see how belief in its divine authority can survive the reading of it.
William JamesPlasticity, then, in the wide sense of the word, means the possession of a structure weak enough to yield to an influence, but strong enough not to yield all at once. Each relatively stable phase of equilibrium in such a structure is marked by what we may call a new set of habits.
William James