  Ren{\'e} Thom discovered several refined topological notions in the writings
of Aristotle, especially the biological. More generally, he considered that
some of the assertions of the Greek philosophers have a definite topological
content, even if they were written 2400 years before the field of topology was
born. In this article, we expand on these ideas of Thom. At the same time, we
highlight the importance of biology in the works of Aristotle and Thom and we
report on their conception of mathematics and more generally on science. The
final version of this article will appear in the book \emph{Geometry in
history} (ed. S. G. Dani and A. Papadopoulos), Springer Verlag, 2019.
