But this kind of discussion must be considered to be due to...

But this kind of discussion must be considered to be due to a looseness of the language, that is, just as, with regard to objective existence and the external world, the causal relation holds between existents, and the external existence of the effect depends upon the external existence of the cause, such a relation can also be imagined in the mental world, in the case that the conception of a whatness depends upon the conception of something else, as the conception of a triangle depends on the conception of line and surface.

An implication of this looseness of language is that one cannot establish that the principles of real and entified causes and effects also apply to them. A similar looseness also can be found in the case of secondary philosophical intelligibles, as when ‘possibility’ is considered to be ‘the cause of need for a cause,’ while neither possibility nor need are entified things, and between them it is meaningless to suppose that there is a real causal relation or influence in the external world.

One of these cannot be considered the cause and the other the effect. What is meant here is that by attending to the possibility of a whatness, the intellect is led to the recognition of this whatness’s need for a cause, not that possibility, which is interpreted as the lack of necessity for existence or nonexistence, has a reality by means of which something else comes into existence called ‘the need for a cause.’ We can conclude from this that the discussion of cause and effect which is presented as being one of the most basic philosophical discussions, in which specific principles for cause and effect are propounded, must be restricted to causes and effects in the external world, and real relationships between them.

If in other cases the expression ‘causation’ is employed, this is due to imprecision or looseness of language. The Impossibility of a Causal Circle One of the topics which is presented pertaining to the causal relation is that it is impossible for any existent, with regard to the aspect in which it is the cause and influence of the appearance of another existent, should be, in that very aspect, the effect and in need of that other existent.

In other words, no cause can be the effect of its own effect. From another perspective, a cause cannot be the cause of its own cause. This may be put in yet another way by saying that it is impossible for an existent to be both cause and effect of another existent.