Some comments on the physico-chemical description of biological activity.

Abstract Contemporary biology is dominated by the view that a complete understanding of biological activity is to be found exclusively by analytical physico-chemical techniques. When the basic assumptions which underlie this view are explicitly stated in full generality, it is seen that they raise important new system-theoretic questions. The investigation of these questions falls outside the scope of analytical biology, and belongs rather to relational biology. We shall show that the class of physico-chemical systems which satisfy the basic assumptions made in analytical biology is extremely limited, and apparently excludes many systems of biological interest.