§ 1. The generality and simplicity of the metaphysical problem make it difficult to define the study. § 2. Problem is suggested by the presence of contradictions in ordinary experience. § 3. By making a distinction between reality and appearance the sciences remove some of these contradictions, but themselves lead to further difficulties of the same sort; hence the need for systematic inquiry into the meaning of the distinction between the real and the apparent, and the general character of reality as such. § 4. Metaphysics, as an inquiry into the ultimate meaning of “reality,” is akin to poetry and religion, but differs from them in its scientific character, from the mathematical and experimental sciences in its method, from common scepticism in the critical nature of its methods as well as in its positive purpose. § 5. The study is difficult (_a_) because of the generality of its problems, (_b_) and because we cannot employ diagrams or physical experiments. § 6. The objection that Metaphysics is an impossibility may be shown in all its forms to rest upon self-contradictory assumptions of a metaphysical kind. § 7. The minor objections that, if possible, the science is superfluous, or at least stationary, may be met with equal ease. § 8. Metaphysics is partly akin to the mystical tendency, but differs from mysticism in virtue of its positive interest in the world of appearances, as well as by its scientific method. § 9. It agrees with logic in the generality of its scope, but differs in being concerned with the real, whereas logic is primarily concerned with the inferrible. §10. The problems of the so-called _Theory of Knowledge_ are really metaphysical.