The first thing to make clear is that scientists, freely making their own choice of problems and pursuing them in the light of their own personal judgment, are in fact co-operating as members of a closely knit organization.

We know more than we can tell.

We could not, for example, arrive at a principle like that of entropy without introducing some additional principle, such as randomness, to this topography.

Theories of evolution must provide for the creative acts which brought such theories into existence.

Personal participation is the universal principle of knowing.

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.