Both physical and moral evil are to be conceived as some form of privation or defect of being, not as positive entity. Their existence is thus not irreconcilable with the doctrine of theistic monism. This is the most frequent use of the name in modern philosophy, where it is commonly contrasted with monism. But it should not be forgotten that dualism in this sense is quite reconcilable with a monistic origin of all things. The theistic doctrine of creation gives a monistic account of the universe in this sense.
Dualism is thus opposed to both materialism and idealism.
Idealism, however, of the Berkeleyan type, which maintains the existence of a multitude of distinct substantial minds, may along with dualism, be described as pluralism. Being alone exists. It is absolutely one, eternal, and unchangeable. There is no real becoming or beginning of being. Seeming changes and plurality of beings are mere appearances.