Aristotle’s Deductive Method

The study of how correct knowledge can be obtained was systematized by Aristotle (384-322 BC) as the science of knowledge, that is, logic. Logic, which was compiled in his Organon, was regarded as an instrument for reaching truth through proper thinking, as a science preliminary to the various other sciences.

According to Aristotle, true knowledge should be obtained through logical proof. He recognized the inductive method as well, in which one proceeds from the particular to the universal; but Aristotle regarded it as less than perfect. He thought that the deductive method, in which the particulars are deduced from the universal, would provide surer knowledge. The fundamental tool of this method is the syllogism, a representative example of which is as follows:

All men are mortal. (Major Premise)
Socrates is a man. (Minor Premise)
Therefore, Socrates is mortal. (Conclusion)

In the Middle Ages, great importance was attached to Aristotle’s logic as an instrument for proving the propositions of theology and philosophy deductively. The Aristotelian syllogism has been recognized for two thousand years, hardly undergoing any change.