Descartes - Rules For The Direction of The Mind
Philosophy from Descartes

RULE VI

In order to distinguish what is most simple from what is complex, and to deal with things in an orderly way, what we must do, whenever we have a series in which we have directly deduced a number of truths one from another, is to observe which one is most simple, and how far all the others are removed from this-whether more, or less, or equally.