 Finally, apparent hypotheses are definitions or conventions rather than actual claims about the world. They therefore may not be considered to be hypotheses at all, although they are, however, often mistaken for hypotheses. Poincaré argues that (metric) geometry is the hypothesis most prone to such confusion. Although he presents arithmetic in Science and Hypothesis without mentioning hypotheses explicitly, we can see a role for them in his analysis here as well, which we will present in the order that he follows.