This paper examines the relevance of Canguilhem's thought regarding changes in the life sciences, and the relationship between science and philosophy. It shows that the concept of vital normality, and its focus on value as essential trait of life, reveals, in biology, a basic problem of knowledge. A nuclear concept in Canguilhem's thought, present in all of his work - as made clear, in 1980, by his contribution at the Conference on the Brain and Thought - it's still actual in present-day discussion of unanswered questions in the neurosciences and in definitions of life. No brief, universal definition of life is generally accepted, in the sciences, as standard definition. To define life as unconscious position of value is not in accordance with the quantitative perspective of natural science. What is value as definition of life ? Can metabolic components present a dimension shown to be inaugurated by human life ? Such questions may only be equations after indispensable changes in the concepts of man and his relationship with knowledge. In the final part, affinity is established between Canguilhem's concept of vital normality and the will to power of Nietzsche. The concept of vital normality links to the will to power as organic life-creating force. To postulate value as previous to man is to uphold the biological reality of thought, from which develops humanity, fulfilling with meaning the experience of life.
Canguilhem; life sciences; philosophy