Thus it is clear that a thing can be made known only through acquaintance with the thing itself or something resembling it. Whoever knows the thing itself has no need of a definition to know it. Whoever does not know it can come to know it through a definition only if he knows something resembling it, even if only in certain respects. Similar attributes shared by it and other things are then combined for him in a way that uniquely identifies the thing being defined. Whoever examines this closely will recognize its truth and understand how people know what they have been told about the unseen: the angels, the Last Day, and the various kinds of bliss and torment in Paradise and Hell. Their account of definition is thereby invalidated.

(Fifth: Simple conceptions cannot be sought and therefore cannot be acquired through definition. For if the mind is already aware of them, seeking them is impossible, since acquiring what has already been acquired is impossible. If it is unaware of them, the soul cannot seek that of which it is unaware, for seeking and intending presuppose awareness.

If it is said: “Yet a person seeks to conceive of angels, jinn, the spirit, and many other things of which he is unaware.”

The reply is: He has heard these names and seeks to conceive of what they denote, just as someone who hears expressions whose meanings he does not understand seeks to conceive of their meanings. When he conceives of what these names denote, he must also know that it is designated by the corresponding name. For if he conceived of a reality without that name being included in the conception, he would not have conceived of what he sought. Here, then, what is conceived is an entity together with the fact that it is designated by such-and-such a name. This is not a conception of the meaning alone, but of both the meaning and its name. There is no doubt that this can be sought. It does not follow, however, that the meaning taken on its own can be sought.