M. Makkai
Towards a categorical foundation of mathematics
https://projecteuclid.org/ebooks/lecture-notes-in-logic/Logic-Colloquium-95--Proceedings-of-the-Annual-European-Summer/chapter/Towards-a-Categorical-Foundation-of-Mathematics/lnl/1235415906in Logic Colloquium '95: Proceedings of the Annual European Summer Meeting of the Association of Symbolic Logic, held in Haifa, Israel, August 9-18, 1995