The first part of this paper highlights some key aspects of the differences in the use of mathematical tools in physics and in biology. Scientific knowledge is viewed as a network of interactions, more than as a hierachically organized structure where mathematics would display the essence of phenomena. The concept of "unity" in the biological phenomenon is then discussed. In the second part, a foundational issue in mathematics is revisited, following recent perspectives in the physiology of action. The relevance of the historical formation of mathematical concepts is also emphasized. Part I: Reflections on Mathematics in Biology Introduction: hierarchies of disciplines. When hearing biologists about working methods in their discipline, one may often appreciate traces of the emotions of a scientific experience of great 1 In Proceedings of the International Symposium on Foundations in Mathematics and Biology: Problems, Prospects, Interactions, Invited lecture, Pontifical Lateran Univer...

this paper, Mathematics is viewed as a "three dimensional manifold" grounded on logic, formalisms and invariants of space; we will appreciate by 1