'Mā huwa?' asks what a thing is: an answer can express its complete essence ('rational animal') or a constituent such as its genus ('animal').
'Ayyu shayʾin huwa fī dhātihī?' seeks the feature by which that thing is intrinsically distinguished within its genus. The answer for the human species is 'rational'.
'Animal' is shared by humans and horses; 'rational' supplies the species-forming difference. Genus and differentia are both intrinsic, but they perform different explanatory roles.
Opening interactive controls...
The Five Predicables: Differentia, Property, Common Accident, Essential and Accidental Attributes
'Mā huwa?' asks what a thing is: an answer can express its complete essence ('rational animal') or a constituent such as its genus ('animal').
'Ayyu shayʾin huwa fī dhātihī?' seeks the feature by which that thing is intrinsically distinguished within its genus. The answer for the human species is 'rational'.
'Animal' is shared by humans and horses; 'rational' supplies the species-forming difference. Genus and differentia are both intrinsic, but they perform different explanatory roles.