The belief in ‘affects.’— Affects are a construction of the intellect, an invention of causes that do not exist. All general bodily feelings that we do not understand are interpreted intellectually; i.e., a reason is sought in persons, experiences, etc., for why one feels this way or that Thus something disadvantageous, dangerous, or strange is posted as the cause of our ill humor; in fact, it is added on to ill humor, in order to render our condition comprehensible. Frequent rushes of blood to the brain accompanied by a chocking sensation are interpreted as ‘anger’: persons and things that rouse us to anger are means of relieving our physiological condition.— Subsequently, after long habituation, certain incidents are so regularly associated with certain general feelings that the sight of certain incidents arouses the corresponding feeling and in particular brings with it this congestion of blood, production of semen, etc., through closeness of association. We then say that ‘the affect is aroused’
Friedrich Nietzsche, The Will to Power, n. 670, 354