The Summa Contra Gentiles was composed by Thomas Aquinas between 1259 and 1265, in four books broadly covering teachings on God, on Creation, on Providence, and on tenets specific to Christianity. This Summa is not to be confused with his final Summa, the Summa Theologiae. The latter is specifically "theological" and directed to a Christian audience (hence Summa "Theologica"), whereas the former, as the "Contra Gentiles" indicates, is directed toward "non-Christian" thinkers. Implicitly a defence of the Catholic Christian faith, the first three books constitute a sort of rational apology of Christian thought, where philosophical arguments are deployed to defend Christian beliefs and usually only evoke Scripture in a latter instance to show its concordance with these largely-rational conclusions; the fourth book, however, is theological in character given that its content deals primarily with topics derived from Christian revelation. Although Thomas Aquinas certainly aims to discredit pagan, Jewish, Muslim or Christian-"heretical" positions incompatible with the Catholic Christian religion in this work, at the same time he incorporates whatever is salvageable from their thought, thus often quoting in his favor the very authors he discredits on other positions: therefore the "Contra Gentiles" of this Summa is not to be understood as an outright rejection of non-Christian thought, but rather as a sort of "rational purification" unto its Catholic assimilation, in disposing open minds to revealed Christian truths. (Summary by M.S.C. Lambert, LC)