Abstract

This chapter argues that two forms of scientific knowledge (_epistēmē_) fall under Aristotle’s definition in _Posterior Analytics_ 1.2: demonstrative scientific knowledge and non-demonstrative scientific knowledge, which Aristotle also calls _nous_. We have demonstrative scientific knowledge when we know that M, which is the cause of the fact that some attribute P belongs to some subject S, is the cause of the fact that P belongs to S and that P belongs to S by necessity (i.e., we know a demonstration). We have non-demonstrative scientific knowledge (i.e., _nous_) when we know that E, which is the essence of S, is the cause because of which S is the very thing that it is and that S is the very thing that it is by necessity (i.e., we know a definition). Aristotle’s account of learning by demonstration is then re-examined in light of this discussion.