I've always thought that the name, "San Pietro Damiani," sounded fun, like a party in the mouth. There's something about how it just flows across the tongue that is quite pleasant. St. Peter Damian, however, would probably not have been a fun saint to hang around with; he was the fiery reforming kind, and introduced a very harsh discipline into his Benedictine monastery (although he would later pull his monks back when, overzealous, they tried to start even harsher disciplines). An uncompromising polemicist and controversialist, he fought simony and clerical immorality in any and all forms, and was one of the most important, and perhaps the most important, theologian of the eleventh century and of what is usually called the Gregorian Reform, for which reason he has been named a Doctor of the Church. Dante admired him as a forerunner of St. Francis, though, and if there is one monk in the eleventh century of absolutely unquestioned integrity, it's Peter Damian, who demanded much of everyone but never demanded of anyone more than he demanded of himself.
One of the important things Peter did was to create one of the standard philosophical problems of the scholastic period: Can God, being omnipotent, make what has happened in the past never to have happened? Apparently some of Peter's monks had asked him this question, and he was the first person to make a serious effort at dealing with the complicated questions about the nature of omnipotence, the nature of possibility, and the nature of time that it raises. All this is found in his letter On Divine Omnipotence, selections of which one can find online in Paul Spade's translation (PDF). There's a good discussion of the philosophical issues in Holopainen's SEP article on Peter Damian.
