The same applies, then, to positing a faith that characterizes no believer, but is stripped of every qualification, or a human being who is neither existent nor nonexistent. In reality, faith exists only in believers, and human nature exists only as an attribute of human beings. Every human being has a human nature particular to him, and every believer has a faith particular to him. Zayd’s human nature resembles Umar’s, but is not identical to it. When they belong to the same human species, this means that the two resemble one another as they exist outside the mind, and share an unqualified universal concept that exists in the mind.

Likewise, when it is said, ‘Zayd’s faith is like Amr’s faith,’ each has his own particular faith. Even supposing faith to be alike in everyone, each believer would still have a faith particular to him. That faith is specific and determinate; it is not faith considered simply as faith, but a particular instance of faith, and that faith admits increase.

Those who deny differences of degree in these matters conceive in their minds an unqualified faith, an unqualified human being, or an unqualified existence, stripped of all the attributes that give it particular determination. They then suppose that this is the faith that exists in people. Yet that conception admits neither differences of degree nor multiplicity in itself, for it is a particular conception present in the mind of the one conceiving it. This is why many of them suppose that things sharing a single feature are one and the same individual entity.

Some of their learned and devout scholars went so far as to treat existence in this same way. They conceived of existing things as sharing in what is denoted by ‘existence.’ Having conceived this in their minds, they supposed that it existed outside the mind just as it did within it. They then supposed it to be Allah, thus identifying the Lord with this existence, which never exists anywhere except in the mind of the one conceiving it, and has no existence outside the mind.