I was reading Prediction, Learning, and Games by Cesa-Bianchi and Lugosi (2006), when I came across the following quote in their preface:

. . beware of mathematicians, and all those who make empty prophecies.
St. Augustine, De Genesi ad Litteram libri duodecim.

This was a bit bizarre, because I had read St. Augustine’s De doctrina christiana where he uses logic. Now, logic didn’t become part of mathematics (mathematical logic) until around the 19th century when De Morgan and Boole started to publish their work. (Leibniz had been working on logic in the 17th century, but it was not widely circulated.)  But still, St. Augustine had been using mathematical ideas, and then yet warned Christians against the evils of mathematics?

It appears that Morris Kline (a wonderful mathematics teacher by the way) might have started the myth with a bad translation from Latin into English.

From wikiquote…

De Genesi ad Litteram

• Quapropter bono christiano, sive mathematici, sive quilibet impie divinantium, maxime dicentes vera, cavendi sunt, ne consortio daemoniorum animam deceptam, pacto quodam societatis irretiant.
  • II, xvii, 37
  • Translation published in Mathematics in Western Culture (1953): The good Christian should beware the mathematician and all those who make empty prophecies. The danger already exists that the mathematicians have made a covenant with the devil to darken the spirit and to confine man in the bonds of hell.
  • Modern translation by J.H. Taylor in Ancient Christian Writers (1982): Hence, a devout Christian must avoid astrologers and all impious soothsayers, especially when they tell the truth, for fear of leading his soul into error by consorting with demons and entangling himself with the bonds of such association.
  • Note: The well known, but incorrect English translation was published on page 3 of Morris Kline’s Mathematics in Western Culture (1953). This book is a favorite with math students and is still in print. The Latin word mathematici derives from the Greek meaning of “something learned” and refers mainly to astrologers. This was the chief branch of mathematics at the time but has been replaced in modern times by a plethora of other branches. According to the Shorter Oxford English Dictionary, 3rd edition, the word “mathematician” still meant astrologer as late as 1710.