essential concomitants, whether inseparable or otherwise. Moreover, we have said that one cannot know that such a thing is a constituent of the quiddity, that it is essential to the quiddity and enters into its very reality, unless the quiddity itself is first conceived.
If it is said: “Merely conceiving the essential attributes suffices for conceiving the quiddity, even though I do not yet know that those attributes are essential,” we reply: How can a person know that these particular attributes, and not others, are the essential ones unless he already knows the very quiddity to which they belong and within which they are embedded? And when he conceives some concomitant attributes, how is he to know that these are the essential properties from which the quiddity and the essence are composed—rather than something else—unless he already knows the essence itself?
Hence the knowledge of the essence, which is the quiddity, is conditional upon knowledge of the essential attributes, while knowledge that certain attributes are essential to this quiddity—rather than merely concomitant—depends on knowledge of the essence. Each therefore depends upon the other; neither the essence is known, nor the essential attributes.
This is a weighty argument that overturns the very basis of their discourse. It shows that they have proceeded by sheer arbitrariness in the classifications they laid down, anchoring them to no scientific principle grounded in reality. They simply decree, “This is essential, that is non-essential,” without any criterion by which the essential can be distinguished from the non-essential—something impossible within the system they have fashioned. It also makes clear that the attributes they claim to be essential yield no knowledge whatsoever of the reality of the subject. Indeed, what they have stated entails that the subject cannot possibly be defined; and if the subject cannot be known except through a definition, while the definition is impossible, then the subject itself is unknowable—an absurd conclusion.
For instance, suppose it is maintained that the reality of man cannot be conceived unless his essential attributes—animality and rationality, as they claim—are first conceived. Yet these very attributes, animality and rationality, will not be known to be his essential properties rather than something else until one knows that his essence cannot be conceived except through them.