Monism and Pluralism

There may be many kinds of monism and pluralism: philosophical, religious, social, political, and cultural.

      Philosophical monism and pluralism include ontological, metaphysical, ethical, and epistemological kinds.
      Ontological monism may be a theory that the world consists of a single substance, while ontological pluralism may be a theory that the world consists of a plurality of substances. 

      Metaphysical monism may be a theory that ultimate reality consists of a single substance, while metaphysical pluralism may be a theory that ultimate reality consists of a plurality of substances. 

      Two important kinds of metaphysical pluralism are substance dualism (or Cartesian dualism), which holds that mind and matter are two different substances, and property dualism (or token physicalism), which holds that mind and matter are not different substances and that mental phenomena are merely properties of physical phenomena.
      Metaphysical monism, or the theory that only one kind of entity constitutes ultimate reality, may be of three kinds: idealistic, materialistic, and neutral.¹ Idealistic monism may a theory that all reality is mental or spiritual, and that the world consists of a single underlying substance that is mental or spiritual. Materialistic monism may be a theory that all reality is material or physical, and that mental phenomena are merely rearrangements of physical matter. Neutral monism may be a theory that physical and mental reality are not intrinsically different, and that all physical and mental phenomena are merely rearrangements of a single neutral substance or element.²
      Ethical monism may be a theory that ethical conduct is (can, or should be) guided by a single ethical principle or value system. Ethical pluralism, on the other hand, may be a theory that ethical conduct is (can, or should be) guided by a plurality of ethical principles or value systems. 

      Epistemological monism may be a theory that there is only one kind of truth or that there is only one consistent set of truths about the world. Epistemological pluralism, on the other hand, may be a theory that there are many kinds of truth and that there may be many consistent sets of truths about the world.

      Religious or theological monism may be a theory or attitude that there is only one true way of looking at God, that there is only one true religion, and that there is only one path to spiritual salvation. On the other hand, religious or theological pluralism may be a theory or attitude that there is more than one true way of looking at God, that there is more than one valid way of discovering ultimate reality, and that there is more than one path to spiritual salvation. 

     It is important to note that religious pluralism does not necessarily entail religious relativism.³ While religious pluralism may involve mutual respect among people of different religions, and may be guided by the principle that people of different religions should be able to live together peacefully in society, religious relativism may be a theory that religious truth is relative to the believer and that all religious beliefs are therefore equally valid. Acceptance of religious pluralism as a social goal or norm does not entail abandonment of the principle that there are absolute moral and religious truths that are not merely a matter of subjective opinion or personal viewpoint.

FOOTNOTES
¹Bertrand Russell, Theory of Knowledge: The 1913 Manuscript, edited by Elizabeth Ramsden Eames, in collaboration with Kenneth Blackwell (London: Routledge, 1992), p. 7.
²Ibid., p. 15.
³Jay Newman, Foundations of Religious Tolerance (Toronto: University of Toronto Press, 1982), p. 47.