"The unconditioned" is a term which, while retaining the same general meaning, admits of various applications, particular or universal. It may be the unconditioned as regards some special relation, or the unconditioned as regards all relations whatever. Thus there may be the unconditioned in Psychology--the human soul considered as a substance; the unconditioned in Cosmology--the world considered as a single whole; the unconditioned in Theology--God in His own nature, as distinguished from His manifestations to us; or, finally, the unconditioned _par excellence_--the unconditioned in Ontology--the being on which all other being depends. It is of course possible to identify any one of the three first with the last. It is possible to adopt a system of Egoism, and to maintain that all phenomena are modes of my mind, and that the substance of my mind is the only real existence. It is possible to adopt a system of Materialism, and to maintain that all phenomena are modes of matter, and that the material substance of the world is the only real existence. Or it is possible to adopt a system of Pantheism, and to maintain that all phenomena are modes of the Divine existence, and that God is the only reality. But the several notions are in themselves distinct, though one may ultimately be predicated of another. The general notion of the Unconditioned is the same in all these cases, and all must finally culminate in the last, the Unconditioned _par excellence_. The general notion is that of the One as distinguished from the Many, the substance from its accidents, the permanent reality from its variable modifications. Thought, will, sensation, are modes of my existence. What is the _I_ that is one and the same in all? Extension, figure, resistance, are attributes of matter. What is the one substance to which these attributes belong? But the generalisation cannot stop here. If matter differs from mind, the _non-ego_ from the _ego_, as one thing from another, there must be some special point of difference, which, is the condition of the existence of each in this or that particular manner. Unconditioned existence, therefore, in the highest sense of the term, cannot be the existence of _this_ as distinguished from _that_; it must be existence _per se_, the ground and principle of all conditioned or special existence. This is the Unconditioned, properly so called: the unconditioned in Schelling's sense, as the indifference of subject and object: and it is against this that Hamilton's arguments are directed.