Complete knowledge, being complete generalization, the lines of all science will necessarily converge, as they approach this generalization, until all sciences coalesce in one science, and all truth is reduced to a single expression in the utterance of the final conception. In accordance with the laws of thinking, this general term is reached by successive omissions of particularizing attributes, until at last we reach Being--the absolute _summum genus_, wholly free from individual attributes, and thereby embracing everything possible to thought, whether material or immaterial. But this _summum genus_ must be predicable of this whole. Matter and mind may thus be reduced to a single category, and the physical and the intellectual finally coalesce in this last generalization. Materialism and idealism thus differ merely in the degree of generalization reached--or rather they both agree in avoiding the final generalization which identifies both matter and mind. Materialism must always deal with the individual, for matter can appear under no other form. Idealism must always rest upon the general, for thought, to be thought, must state a generalization. Each, however, finds its explanation in the other, and both are harmonized by the application of the law of intellectual action above given. Matter and Mind are complementary, not incompatible. They differ with each other, but they agree in being similarly related to a third term. Matter is objective; it is thought taking form, becoming individual, manifesting itself in space. Mind is subjective. The one appeals to the senses; the other is known only to the consciousness. Science reaches its full development only when it includes both physical and intellectual phenomena within its scope. Every step which it takes carries it further from the purely physical, and brings it nearer the purely intellectual--that is the development of physical science is from the individual towards the general, and it reaches its end, its completion, only when the last distinction, that of subjective and objective, has disappeared in the last possible generalization. When the objective has been identified with the subjective, the distinction between Mind and Matter has been obliterated, and we have reached the Supreme Intelligence--the "I Am" of Scripture--simple Being.