Certain Jesuit Scholastics of the seventeenth century pursued some interesting ideas on the problem of induction. In theory, they take up the problem where Scotus and Ockham left it and take no notice of purveyors of novelties like Descartes, but in fact their problem is very like Descartes’ one of predicting the behavior of clocks whose internal mechanisms one does not know but whose past behavior one has observed.