Abstract
In the first part of my analysis, I wish briefly to clarify the different modes of relation found in the living being, and point out the multiplicity of disciplines in which biologists use (explicitly or implicitly) the notion of laws.
In the second part, I shall analyse the notion of universal laws in biology and examine successively: (1) accidental generalizations; (2) non-causal biological correlations; (3) the meaning of 'necessity' in these correlations; and (4) causal connections. Finally, in the third part, I shall examine statistical laws and probabilistic laws in biology, in particular: (1) chance in biology; (2) probabilistic theories; and (3) relations between logical probability and statistical probability.