In his Ontology book, Mario Bunge defines a 'bare individual' as a real thing stripped of all its properties but endowed with the capacity of associating. Then he interprets the totality of bare individuals as a semigroup with a pairwise association. The multiplication table of this operation clearly distinguishes between different bare elements, they are 'named' with numbers. But if a bare element has no properties, how could it be distinguished from another bare element? It seems like a contradiction to me. What am I missing?