It may seem surprising and shocking to find Pascal recommend a course of action in which we should do things which we don't believe in, in order to become like animals.   But Pascal has suspicions about human reason, questioning its power, and stressing its limits.   There is another very well-known saying of his (op. cit. ed. Brunschvig, p. 458, §277:  "Le coeur a ses raisons que la raison ne connaît point":  "The heart has its reasons which reason itself does not know" (Levi's translation, p. 158).  This sentence is written upside down on the fourth side of the same piece of paper as the Wager.