Materialism belongs to the class of monist ontology. As such, it is different from ontological theories based on dualism or pluralism. For singular explanations of the phenomenal reality, materialism would be in contrast to idealism, neutral monism, and spiritualism.
Is there an answer to this question (If it cannot be answered, say "unanswerable"): Materialism is the same as idealism, neutral monism, and what else?
unanswerable