Is “the Survival of the Fittest” an Empty Tautology?

A common objection to Darwin’s theory is that it depends on a truism and therefore fails to make a scientific, empirical claim. Darwin argues that those who are the fittest survive long enough to reproduce. But who are the fittest? According to creationists Henry and John Morris — and they are certainly not alone in saying this — “the only pragmatic way to define ‘the fittest’ is ‘those who survive’.”

But if “the fittest” are by definition those that survive, then “survival of the fittest” really means “survival of those who survive” — and that is completely unenlightening. Since it is a tautology, it is true no matter what, and therefore doesn’t tell us anything about the way things actually are: whether evolution or creationism is true, those that survive are those that survive.

As evolutionist Robert Pennock points out, the Morrises weren’t sufficiently logical to remain consistent in their criticism: shortly after raising the above objection, they claim that — as part of “the Creator’s plan” for preventing the spread of harmful mutations — natural selection does weed out the unfit. Yet on their view, who are the unfit if not those that die out? Other creationists have been more careful, however. And either way, the challenge remains: Why isn’t “the survival of the fittest” an empty tautology?

It’s not helpful to point out that the catchphrase “survival of the fittest” wasn’t Darwin’s, but Herbert Spencer’s. Other evolutionists — including Darwin himself — use the phrase. And besides, the same objection could be raised with respect to the concept of natural selection without using Spencer's expression.

The concept of natural selection is not circular, however, because “the fittest” are not really defined as “those that survive.” Rather, they are those that have traits that make them more likely to survive. And “survival of those that have traits that make them more likely to survive” is not an empty tautology. It means that there is a difference between those that usually survive long enough to reproduce and those that do not. The former have certain characteristics that the latter lack.

As to what these traits are, that’s an empirical question. But it’s important to realize that they are not defined as the single characteristic of “being more likely to survive.” Natural selection therefore is far from an empty claim.