Reply To: All or some


Remember, definitions are invariably universal, so, “triangles are plane figures bounded by three straight lines” and “gold is a metal” can only sensibly be taken as universal. If someone said to me “triangles have 3 x 60 degrees angles” I’d say, “You are talking about equilateral triangles, aren’t you?” If there’s no way on interviewing your interlocutor, you could take this proposition (as I think you are suggesting) as being an elliptical “(Some) triangles have 3 x 60 degree angles” and thus true or, alternatively, as a quasi-definition and thus false.