Khayyam’s Philosophy Series: Principal subjects of philosophy

There are three essential subjects which are discussed in philosophy.

Is it? (does it exist?)

and that is the question of being and the answer to that is either yes or no. e.g. does the intellect exist? and the answer is yes.

What is it?

and that’s a question about the reality and quiddity of a thing. e.g. what is the reality of the intellect? the answer here is not a yes or no but it is given in three ways:

1. Essential definition, genus and differentia (hadd)
   e.g. What is Human? genus = animal, differentia = rational or intellect => definition = man is a rational animal
2. Descriptive definition via accidents or properties (rasm)
   e.g. property = laughter (laughter is not an essence and comes from rationality) => man is a being that laughs
   e.g. accidental features = two legs, two hands, no wings => Man is a being with two legs, no wings, and walks upright.
3. Explanation of the name (sharh al-ism)
   e.g. Man is a word we use to signify a species of rational being like ourselves (it is a linguistic usage)

Why is it thus?

and that is the question of the cause, the cause by which the thing has come to existence. e.g. why does the intellect exist? and here also the answer is not a yes or no but requires causal explanation. This is often broken down into Aristotle’s four causes: material, formal, efficient, and final.

1. e.g. why does the intellect exist => The intellect exists because the Necessary Existent (efficient) emanates it as an immaterial faculty (material), whose purpose is to apprehend universals (formal) and direct the soul toward perfection (final).

References / Origin

• Summarised from: Risāla fī al-Kawn wa al-Taklīf (On the World and the Duty)