Where the properties of two persons are united after such a manner as neither to admit of _division_ nor _separation_, as when one builds a house on another's ground, in that case the whole must belong to one of the proprietors; and here I assert, that it naturally is conceived to belong to the proprietor of the most considerable part. For, however the compound object may have a relation to two different persons, and carry our view at once to both of them, yet, as the most considerable part principally engages our attention, and by the strict union draws the inferior along it; for this reason, the whole bears a relation to the proprietor of that part, and is regarded as his property. The only difficulty is, what we shall be pleased to call the most considerable part, and most attractive to the imagination. This quality depends on several different circumstances which have little connexion with each other. One part of a compound object may become more considerable than another, either because it is more constant and durable; because it is of greater value; because it is more obvious and remarkable; because it is of greater extent; or because its existence is more separate and independent. 'Twill be easy to conceive, that, as these circumstances may be conjoined and opposed in all the different ways, and according to all the different degrees, which can be imagined, there will result many cases where the reasons on both sides are so equally balanced, that 'tis impossible for us to give any satisfactory decision. Here, then, is the proper business of municipal laws, to fix what the principles of human nature have left undetermined. The superficies yields to the soil, says the civil law: the writing to the paper: the canvas to the picture. These decisions do not well agree together, and are a proof of the contrariety of those principles from which they are derived.