Naturalism is the name given to those systems of the philosophy of nature which explain the phenomnena by a blind force acting necessarily. This doctrine is to be found in Lucretius, and was held by Leucippus and Epicurus. The Systfee de la Nature of D'Holbach, the Traite de la Nature of Robinet, and the Philosophie de la Nature of Delisle de Sales, also contain it. In theology the term naturalism is applied to all those forms of belief or speculation which deny the doctrine of a personal God as the author and governor of the universe; being thus opposed to Theism (q.v.). See Literature appended to article SEE NATURAL THEOLOGY.