The true explanation of this subject is very difficult. Intellectual things are those which have no outward existence but are conceptions of the mind. For example, mind itself is an intellectual thing which has no outward existence. All man's characteristics and qualities form an intellectual existence and are not sensible. Briefly, the intellectual realities, such as all the qualities and admirable perfections of man, are purely good, and exist.
Evil is simply their nonexistence.
All these things have no real existence. The epitome of this discourse is that it is possible that one thing in relation to another may be evil, and at the same time within the limits of its proper being it may not be evil. When man no longer receives life, he dies. Light is an existing thing, but darkness is nonexistent. Wealth is an existing thing, but poverty is nonexisting.