2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/102294In the paper I check approaches to identity in mathematics by Plato, Frege, and Geach against Category theory.71 pages, 7 figures; in this second version I added new stuff concerning Classes, Individuals, Fibred Categories and Higher CategoriesCategory Theory15Axxtext