The complexity of living bodies and the structure of biological theories

It has been suggested that biological theories differ from physical theories because the subject matter of biology differs from the subject matter of physics especially in the fact that living bodies are more complex than nonliving bodies. It is shown that the interactional complexity of living bodies can only be expressed by invoking biological theories. The claim that living bodies are complex is, therefore, ultimately a claim about the nature of scientific theories rather than a claim about the nature of the subject matter of biology resting upon a presystematic judgement.