Bishop Butler, [Butler, 1736], said that probability was the very guide of life. But what interpretations of probability can serve this function? It isn’t hard to see that empirical (frequency) views won’t do, and many recent writers-for example John Earman, who has said that Bayesianism is “the only game in town”-have been persuaded by various dutch book arguments that only subjective probability will perform the function required. We will defend the thesis that probability construed in this way offers very little guidance, dutch book arguments notwithstanding. We will sketch a way out of the impasse.

Scribal copying is investigated as a test case for the memetic and epidemiological models for explaining the distribution of cultural items. We may hypothesize that the incidence of errors could be low enough to allow two conditions for neo-Darwinian explanation (or an analogue of it) to be fulfilled: first, that there be a rather reliable mechanism for heredity, and second that occasional mutations might produce a version more likely to survive and be propagated than the exemplar. Scriptorial conventions are reviewed. Textual criticism is investigated. Finally, some attention is given to the psychology of language perception and production. In conclusion, it is argued that the memetic model for cultural transmission is not generally fecund while the epidemiological model is.