The quality of a thing is denoted by the Ablative with an adjective or genitive modifier.

This is called the Descriptive Ablative or Ablative of Quality: — It was originally instrumental and appears to have developed from accompaniment (§ 413 ) and manner (§ 412 ). animō meliōre sunt gladiātōrēs (Cat. 2.26) , the gladiators are of a better mind. quae cum esset cīvitās aequissimō iūre ac foedere (Arch. 6) , as this was a city with perfectly equal constitutional rights. mulierem eximiā pulchritūdine (Verr. 2.1.64) , a woman of rare beauty. Aristotelēs, vir summō ingeniō , scientiā , cōpiā (Tusc. 1.7) , Aristotle , a man of the greatest genius, learning , and gift of expression. dē Domitiō dīxit versum Graecum eādem sententiā (Deiot. 25) , concerning Domitius he recited a Greek line of the same tenor. The Ablative of Quality (like the Genitive of Quality, § 345 ) modifies a substantive by describing it. It is therefore equivalent to an adjective, and may be either attributive or predicate. In this it differs from other ablatives, which are equivalent to adverbs.