 Each of these bullet points raises a host of further questions, but, in broad outline, Aquinas understands scientia as the apprehension, with certainty, of an entity, event or proposition, based on a demonstrative proof grounded in the essential nature of the thing in question. As befits intellectual understanding (§6.2), scientia will concern universal truths. Because it concerns the essences of things, it will concern necessary truths and will get at the underlying cause of a thing’s being so (MacDonald 1993).