since what is understood from a definition and a name is the thing defined and the thing named, just as “essence” is what is stated in answer to “What is it?” It is also described as the answer to a question formulated as “What is it?” Thus, essence is the definition, and it is also the thing itself. These verbal nouns derived from interrogative expressions are later coinages, such as māhiyya and mā’iyya (whatness), kayfiyya (howness), haythiyya (respect or aspect), ayniyya (whereness), and limmiyya (whyness). They are comparable to verbal nouns derived from declarative expressions, such as hawqala (saying “There is no power nor strength except through Allah”), qalhada, basmala (saying “In the name of Allah”), hamdala (saying “Praise be to Allah”), and the like.

They then said that “essence” is composed of essential attributes. They explained the distinction between essential and accidental attributes by saying that “essential” attributes are those without conceiving which it is impossible to conceive the thing possessing them. The thing therefore depends on them both in existence and in conception, as an animal depends on corporeality. Whatever is not of this kind is “accidental.”

An accidental attribute is then divided into an inseparable attribute and a separable accident. An inseparable attribute is either inseparable from the essence, as evenness is from four and oddness from three, or inseparable from its existence rather than its essence, as blackness is from pitch and coming into existence is from an animal. A separable accident either passes away slowly, like youth and greying hair, or quickly, like the redness of embarrassment and the pallor of fear.

The difficulty lies in distinguishing an essential attribute from an attribute inseparable from the essence, since neither is separable from the thing itself, whether in external existence or in the mind.