Discoveries are made by pursuing possibilities suggested by existing knowledge.

Admittedly, scientific authority is not distributed evenly throughout the body of scientists; some distinguished members of the profession predominate over others of a more junior standing.

The information in DNA could no more be reduced to the chemical than could the ideas in a book be reduced to the ink and paper: something beyond physics and chemistry encoded DNA.

Admittedly, the body of scientists, as a whole, does uphold the authority of science over the lay public. It controls thereby also the process by which young men are trained to become members of the scientific profession.

These maxims and the art of interpreting them may be said to constitute the premisses of science but I prefer to call them our scientific beliefs. These premisses or beliefs are embodied in a tradition, the tradition of science.

Discoveries are made by pursuing possibilities suggested by existing knowledge.

And the actual achievements of biology are explanations in terms of mechanisms founded on physics and chemistry, which is not the same thing as explanations in terms of physics and chemistry.