Demon or daemon from dictionary:

1 a : an evil spirit b : a source or agent of evil, harm, distress, or ruin

2 an attendant power or spirit : genius

3 mythology : a supernatural being whose nature is intermediate between that of a god and that of a human being

4 : one that has exceptional enthusiasm, drive, or effectiveness

5 : a software program or process that runs in the background

If we stick to the most factual definition it should be the fifth, a software program. We can describe it as a program or part of a program that waits that certain conditions are met and then starts automatically.

We are being programmed with demons to react to certain situations automatically, or according to the program instructions. After realization of certain conditions the demon causes an emotion and transforms a thought into a word, and according to the demon the mind processes thought words related to the emotion.

A man possessed by a demon has it's course being steered - cursed.

Education = the process of forming mental habits of the personality, to obey a certain order ≃ demon formation process