Abstract

The paper examines the main trends in the search for a theory of general biology throughout the 20th century — the physicalization on one hand, and the semiotization on the other. These two approaches had their predecessors and were formed already in the 19th century biology, as Darwinian and Baerian biology. In theoretical biology, there are co-existing (however, asymmetrical) trends toward specifying solutions and generalizing axioms. The inclusion of the biological organism as a subject into biological theory requires an analysis of the concept of scientific fact. A cross-disciplinary typology of facts on the basis of their invariant features is provided. The main periods of development of theoretical biology are briefly characterised, and the trend towards the theory of biological communication and meaning outlined.