Materialism is opposed to idealism since, while idealism holds that the spititual or ideal is prior to the material, materialism holds that matter is prior. This difference manifests itself in opposed ways of interpreting and understanding every question, and so in opposed attitudes in practice. While idealism takes many subtle forms in the writings of philosophers, it is at bottom a continuation of belief in the supernatural. It involves belief in two worlds, in the ideal or supernatual world over against the real material world. In essence idealism is a conservative, reactionary force; and its reactionary influence is demonstrated in practice. Marxism adopts a consistent standpoint of militant materialism.