That there might be yet other spirits besides our own souls cannot be proven
by reason through experience, because with experiences existence is always presupposed
with certainty, and one cannot infer their existence from uncertain
effects. E. g., in the highest mountains one often finds large piles of sea mussels
that could not have come from the biblical flood, therefore some maintain that
apes carried them there, others that, during the time of the Crusades, they dined
here on oysters and threw away the shells. This is always more likely than that
the devil made them, since one is not as convinced of his existence as of apes and
oysters. The following are, therefore, to be rejected