Tag Archives: Karl Popper

The cosmological multiverse and falsifiability in science

The cosmological “multiverse” model talks about regions far beyond the observable portion of our universe (set by the finite light-travel distance given the finite time since the Big Bang). Critics thus complain that it is “unfalsifiable”, and so not science. Indeed, philosopher Massimo Pigliucci states that instead: “… the notion of a multiverse should be classed as scientifically-informed metaphysics”.

Sean Carroll has recently posted an article defending the multiverse as scientific (arXiv paper; blog post). We’re discussing here the cosmological multiverse — the term “multiverse” is also used for concepts arising from string theory and from the many-worlds interpretation of quantum mechanics, but the arguments for and against those are rather different. Continue reading


Yes of course “survival of the fittest” is tautological!

If one phrase could be said to have percolated into popular consciousness as summing up Darwin’s theory of natural selection, that phrase would be “survival of the fittest”. Which is rather a pity since that phrase is not how scientists state the principles of Darwinism. That’s because the phrase is tautological.

In Darwinian terms “fitness” is the ability to survive and reproduce. As stated by H. Allen Orr: “In the crudest terms, fitness involves the ability of organism … to survive and reproduce in the environment in which they find themselves”.1

Given that “fitness” is the tendency to survive and reproduce then, obviously, it is the fittest who tend to survive and reproduce. The maxim “survival of the fittest” is thus a tautology.

And boy has that caused problems!    Not, I might add, problems for biologists, but problems for some who comment on biology, from creationists to philosophers of science. I had been under the impression that all this had been clarified decades ago, but on reading the article on biological fitness in the Stanford Encyclopedia of Philosophy, written in 2015 by Alex Rosenberg and Frederic Bouchard, I was surprised to find that this is still a live issue among philosophers.

The worry is that, if the phrase “survival of the fittest” is tautological, then perhaps the whole concept of Darwinian “fitness” is tautological and thus empty of any actual content, and then maybe the whole of Darwinism becomes “metaphysics” rather than science. This accusation has been made by creationists, and even by luminaries such as Sir Karl Popper.

The reply is actually quite simple: Yes, the phrase “survival of the fittest” is tautological; but no, the concept of “fitness” is not tautological, and nor is Darwinian natural selection. That’s it; that’s the resolution of the “problem”. Continue reading