Ἐπιστήμη

In the Analytics Aristotle says that one science is judged to be more accurate than another in two ways.¹ First, when one science demonstrates the principles of another one. For example, physiology is more accurate than medicine. In the same fashion, for the same reason, geometry also is more accurate than mechanics, and arithmetic is more accurate than harmonics. According to another account, one science is more accurate than another because its underlying subject is immaterial. So not only geometry but also arithmetic and theology are among the sciences which underlie those with material subjects. For this reason Aristotle also says in Metaphysics that the theoretical consideration of intelligible things is both easy and difficult.² It is easy because it deals with the present facts, that is to say the things that always are in the same way. Certainly the divine things are the most evident, insofar as they are not subject to change at all in substance, in potentiality and in activity. Now this is why it is easy. On the other hand, it is difficult on account of our weakness, for we are unable to reach towards their light because we have a body and affections. Such a thing is what bats undergo with regard to the sun as well.³
Science is a disposition of character in the acceptance without dissimulation of presentations.⁴
Aristotle calls "philosophical sciences" physics, logic, ethics and metaphysics. But the understanding of the thing itself [is] also science.⁵