Abstract

There is a very plausible principle of the transitivity of justifying reasons. It says that if "p" is better justified than "q" (all things considered) and "q" better than "r", then "p" is better justified than "r" (all things considered). There is a corresponding principle of rational theory choice. Call one theory "a better theory than" another theory if all criteria of theory choice considered (explanatory power, simplicity, empirical adequacy, etc.), the first theory meets the criteria better than the second theory. The corresponding transitivity principle says that if theory A is a better theory than theory B and if theory B is a better theory than theory C, then A is a better theory than theory C. I argue against this principle. It turns out that whenever there are 2 or more relevant and independent criteria of theory evaluation, and whenever at least of one the criteria is "non-linear" in a certain sense, there may be violations of transitivity which do not violate any standards of rationality (of theory choice). This shows, again, that theory choice cannot be seen as merely the application of given rules of rational theory choice.