The Philosophy of Law: Supplementary Explanations, I: Logical Preparation for the Preceding Conception of Right
If philosophical Jurists would rise to the Metaphysical Principles of the Science of Right, without which all their juridical Science will be merely statutory, they must not be indifferent to securing completeness in the Division of their juridical conceptions. Apart from such internal completeness their science would not be a rational System, but only an Aggregate of accidental details. The topical arrangement of Principles as deter mined by the form of the System, must therefore be made complete; that is to say, there must be a proper place assigned to each conception (locus communis) as determined by the synthetic form of the Division. And it would have to be afterwards made apparent that when any other conception were put in the place of the one thus assigned, it would be contradictory to itself and out of its own place.
Now Jurists have hitherto received only two formal commonplaces in their Systems, namely, the conceptions of Real Right and of Personal Right. But since there are other two conceptions possible even a priori by a mere formal combination of these two as members of a rational Division, giving the conception of a Personal Right of a Real Kind, and that of a Real Right of a Personal Kind,—it is natural to ask whether these further conceptions, although viewed as only problematical in themselves, should not likewise be incorporated in the scheme of a complete Division of the juridical System? This in fact does not admit of doubt. The merely logical Division, indeed, as abstracting from the object of Knowledge, is always in the form of a Diclwtomy; so that every Right is either a Real or a not-Real Right. But the metaphysical Division, here under consideration, may also be in the fourfold form of a Tdrachotomy; for in addition to the two simple members of the Division, there are also two relations between them, as conditions of mutual limitation arising from the one Right entering into combination with the other; and the possibility of this requires a special investigation.—But the conception of a Real Right of a Personal Kind falls out at once; for the Right of a Thing as against a Person is inconceivable. It remains, therefore, only to consider, whether the converse of this relation is likewise inconceivable; or whether the conception of a Personal Right of a Real Kind is not only free from internal contradiction, but is even contained a priori in Reason and belongs as a necessary constituent to the conception of the external Mine and Thine in its completeness, in order that Persons may be viewed so far in the same way as Things; not indeed to the extent of treating them in all respects alike, but by regard to the possession of them, and to proceeding with Persons incertain relations as if they were Things.