What do particular qualities refer to in Aquinas' philosophy?

In Aquinas' philosophy, particular qualities refer to the unique characteristics that distinguish each individual entity from others. This concept is rooted in his understanding of metaphysics and the way he categorizes entities within the framework of substance and essence. While Aquinas acknowledged universal principles and the shared characteristics of categories, it is the particular qualities that highlight individual differences.

Each entity possesses specific traits that define its existence and individuality, which aligns with the essence of that being. This emphasis on uniqueness is crucial in Aquinas' discussions about the nature of beings, as it allows for the recognition of diversity within the broader categories of existence.