The familiar slogan "survival of the fittest" is popularly used to express the claim, often mistakenly attributed to evolutionary biologists, that the fittest are most likely to survive. However, biologists use the term "fittest" to mean "most likely to survive, " so the slogan is merely claiming that the most likely to survive are the most likely to survive. While this claim is clearly true, it is a tautology and so is neither informative nor of scientific interest. The argument above depends on assuming which one of the following? ['Only claims that are true are of scientific interest.', 'Informative scientific claims cannot use terms in the way they are popularly used.', 'Popular slogans are seldom informative or of scientific interest.', 'The truth of a purported scientific claim is not sufficient for it to be of scientific interest.']