ported by possession was impossible; and the question of compatibility was so closely reasoned through all its possible ramifications that there are few minor topics in any science that have elicited a more searching analysis, or which present a greater mass of subtle distinctions.
Of the body of abstruse rules thus evolved, it will be impossible within the limits of this paper to convey any adequate conception. It may be explained, however, that the door through which future estates were admitted into our law was the theory that the perpetual right of enjoyment implied from possession was an entire estate, which, by words used at the time of delivery, could, in point of time, be carved up into a number of fractions, to be successively enjoyed by different persons; and that as all these persons combined took only one entire estate, a single delivery would suffice for all, the taker of the first fraction being construed to receive the possession on behalf of all. Thus if delivery of land to A were accompanied by declaration or deed to the effect that A should have it for a term of years, then B for his life, the remainder of the estate after B's death to go to C and his heirs forever, these future estates to B and C were deemed valid, because B and C were regarded as in on the possession delivered to A.
This theory was countenanced only upon the ground that the total of the several fractional estates, thus created by a single act, was precisely equivalent to the one perpetual and uninterrupted right of enjoyment, which could be conferred upon one person by a single delivery. Any proposed future estate which could not be justified by a strict application of this theory was legally impossible. Hence, if by the terms of the delivery, or by reason of any subsequent contingency, the several fractions were not, or ceased to be, the exact equivalent of one entire estate, the future estates either never arose, or forthwith collapsed. There could, therefore, be no future estate, unless supported by a prior and present estate created by the same act; and each fractional estate must be such as to take effect in possession immediately upon the determination of the next preceding estate; otherwise it was void, and necessarily involved all succeeding estates in the ruin.
This stringent limitation arose into great importance, and indeed became the source of a large part of the law of future estates, when at a later day, upon grounds unnecessary and perhaps difficult to reproduce, it was held permissible to create future estates, doubtful or contingent as to the time when, or persons in whom, they should vest. Thus delivery might be made to A for his life, then to go for life to B's eldest son (not yet born), then forever to C and his heirs. Here it was a matter of contingency when, if ever, B would have a son. If A died before the birth of