Step 1: Can the concept apply to multiple individuals? If yes, it is universal.
Step 2: Does it signify the complete essence of those individuals? If yes, it is essential.
Step 3: If it is not the whole essence, is it a conceptual component? If yes, it is still essential; otherwise it is accidental.
Applied to Zayd: 'human' is the whole essence, 'rational' a constituent, and 'learned' an external attribute.
Opening interactive controls...
Worked procedure: classify in three questions
Essence, Quiddity, and Essential vs Accidental Universals
Step 1: Can the concept apply to multiple individuals? If yes, it is universal.
Step 2: Does it signify the complete essence of those individuals? If yes, it is essential.
Step 3: If it is not the whole essence, is it a conceptual component? If yes, it is still essential; otherwise it is accidental.
Applied to Zayd: 'human' is the whole essence, 'rational' a constituent, and 'learned' an external attribute.