the sun. At one time this was called the Copernican theory; but, when
evidence for a theory becomes so overwhelming that no informed person
can doubt it, it is customary for scientists to call it a fact. That all
present life descended from earlier forms, over vast stretches of geologic
time, is as firmly established as Copernican cosmology. Biologists differ
only with respect to theories about how the process operates.
- Martin Gardner, "Irving Kristol and the Facts of Life",
The Skeptical Inquirer, Vol. XII No. 2, ppg. 128-131