William James on will (in Varieties of Religious Experience):

“When we drop abstractions and take what we call our will in the act, we see that it is a very complex function. It involves both stimulations and inhibitions; it follows generalized habits; it is escorted by reflective criticisms; and it leaves a good or a bad taste of itself behind, according to the manner of the performance. The result is that, quite apart from the immediate pleasure which any sensible experience may give us, our own general moral attitude in procuring or undergoing the experience brings with it a secondary satisfaction or distaste. Some men and women, indeed, there are who can live on smiles and the word “yes” forever. But for others (indeed for most), this is too tepid and relaxed a moral climate. Passive happiness is slack and insipid, and soon grows mawkish and intolerable. Some austerity and wintry negativity, some roughness, danger, stringency, and effort, some “no! no!” must be mixed in, to produce the sense of an existence with character and texture and power. The range of individual differences in this respect is enormous; but whatever the mixture of yeses and noes may be, the person is infallibly aware when he has struck it in the right proportion FOR HIM. This, he feels, is my proper vocation, this is the OPTIMUM, the law, the life for me to live. Here I find the degree of equilibrium, safety, calm, and leisure which I need, or here I find the challenge, passion, fight, and hardship without which my soul’s energy expires.”