 The specific nature (or essence) can be conceived from a twofold point of view: intensionally (in abstracto) and extensionally (in concreto). Intensionally viewed, the specific nature simply expresses the set of essential properties that compose a categorial form, without any reference to the existence of individuals which, if there are any, instantiate it. Extensionally viewed, the specific nature is that same form conceived of as instantiated by at least one singular entity. For instance, human nature intensionally considered is humanity (humanitas); extensionally it is man (homo) (In Porph., prooem., fol. 9va). Both of them are substantial forms superordinated to the whole human compound, but while humanity is properly a form, i.e. something existentially incomplete and dependent, man is an existentially autonomous and independent entity. Thus they differ from each other in the same way as a predicate (for example ‘P’) differs from a formula (for example, ‘P(x)’).