without first conceiving of its rationality, whereas conceiving of its capacity for laughter is not required.”

They may be answered:

This is not correct. Such an ordering is scarcely found except among those who accept these definitions on your authority, following you in the matters you have made the standard for judging intelligible things. Otherwise, neither attribute may occur to a person, or one may occur without the other, and vice versa.

Even if both attributes occur to someone, and he knows that a human being is a rational animal capable of laughter, merely knowing these attributes does not mean that he has grasped the essence of a human being at all. All this is evident to sense and reason. Let no rational person deceive himself about it out of deference to these people, who are among the most misguided of all creatures despite their claims to rigorous inquiry. Among the ancients, they are like the speculative theologians of Islam among the later generations. Since Muslims are better than the followers of the two Scriptures and the Sabians, their theologians are better, more knowledgeable and wiser than those philosophers. Reflect on this, for it is immensely beneficial.

Hence they say:

“Essential definitions are difficult, and discerning essential attributes is hard. Most definitions people possess are descriptive definitions.”

All this is because they have drawn a distinction between two things solely through an arbitrary stipulation of their own making.

It is well known that whatever has no reality either in the external world or in thought, but is merely a fabricated innovation devised to distinguish between two like things precisely in the respect in which they are alike—cannot be grasped by minds