In order to acquire the knowledge of the true and primary principles of scientific knowledge, and especially the intelligence of the universal essence of the subject, which is always true, the process of knowledge consists of (I) sense (a'lcO o s), which receives the essence as individual, (2) memory (uvi j), which is a retention of sensible impression, (3) experience (cµirecpia),which consists of a number of similar memories, (4) induction (brayw-y), which infers the universal as a fact (TO iTC), (5) intellect (vas), which apprehends the principle (apxit); because it is a true apprehension that the universal induced is the very essence and formal cause of the subject: thereupon, scientific syllogism (i rcnf µovucos vvXXoycvµos), making the definition (opeg ios) of this essence the middle term (TO, c Vov), becomes a demonstration (6.7rOSee es) of the consequences which follow from the essence in the conclusion.