A 'term of intelligence' (intelligibile) is what answers to a universal concept: it is the scientific aspect of a thing (ratio, [Chap. XLVIII note I]), what we call the 'principle' of a thing, as of 'youth,' 'manhood,' 'tree,' 'steam-engine,' as distinguished from the embodiment of that principle in these and those particular materials. It is the logos, not the pathê. It is what some think Plato to have meant by an 'idea.'

Of God and His Creatures: 2.96