Full Idea
The misunderstanding of passion and reason, as if the latter were an independent entity and not rather a system of relations between various passions and desires; and as if every passion did not possess its quantum of reason.
Gist of Idea
We fail to see that reason is a network of passions, and every passion contains some reason
Source
Friedrich Nietzsche (The Will to Power (notebooks) [1888], §387)
Book Reference
Nietzsche,Friedrich: 'The Will to Power', ed/tr. Kaufmann,W /Hollingdate,R [Vintage 1968], p.208
A Reaction
This seems to me a much more accurate account of the relation of reason and passion than almost anything in earlier philosophy (though Aristotle is quite good on it). I am retraining myself to see my mental life in this way.