The fact that two concepts apply to Zayd does not establish equality. Both “human” and “animal” apply to him, yet it does not follow that every animal is human.
Equality requires that neither concept have even one instance outside the other.
If one counterexample appears in either direction, equality fails. We must then determine whether the difference exists only on one side or on both sides to identify the correct remaining relation.
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Four Relations Between Universals and Relative Particularity
The fact that two concepts apply to Zayd does not establish equality. Both “human” and “animal” apply to him, yet it does not follow that every animal is human.
Equality requires that neither concept have even one instance outside the other.
If one counterexample appears in either direction, equality fails. We must then determine whether the difference exists only on one side or on both sides to identify the correct remaining relation.