Plasticity, 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 JamesBoth thought and feeling are determinants of conduct, and the same conduct may be determined either by feeling or by thought.
William JamesThe first thing to learn in intercourse with others is non-interference with their own particular ways of being happy, provided those ways do not assume to interfere by violence with ours.
William James