T bequeaths property "to my son S, but if S dies without children, then to my daughter D." Analyze the interests created.

This is one of the most instructive problems in the law of property, because it sits at the intersection of three distinct doctrines — vested interest, conditional limitation under Section 28, and the rule governing divesting conditions.

S's Interest: Vested, Yet Defeasible

The first thing to notice about this bequest is that T gives the property to S in terms that appear absolute. There is no condition that S must first perform before receiving the property — no prior contingency to fulfil, no uncertain event to survive. The interest vests in S the moment T's death occurs and the bequest takes effect. This is a classic vested interest within the meaning of Section 19 of the Transfer of Property Act, 1882, which recognises an immediate right in the transferee, even if enjoyment may be subject to future conditions.

But the bequest does not stop there. It adds the clause "but if S dies without children," which is a condition superadded to an already vested estate. This is a condition subsequent — it does not prevent vesting but operates, if fulfilled, to terminate S's interest after it has already arisen. Such a device is what the Act, in Section 28, calls a conditional limitation: a condition of defeasance that terminates the interest of one person and vests it in another. The courts have consistently described this category of interest as a vested interest liable to be divested. The Allahabad High Court beautifully articulated this in Sunder Bibi v. Rajendra Narain (AIR 1925 All 389) — where it was held that a provision for a gift over to another person, upon a contingency, had the effect of creating a vested interest in the first taker, because the condition affected "the retention of the interest and not its acquisition." S acquires full ownership when T dies; the question is only whether he will keep it indefinitely.

D's Interest: Contingent Under Section 21

D's position, on the other hand, is entirely dependent on an uncertain future event — the death of S without leaving children. Until that event occurs, D has no present right to the property. This is the hallmark of a contingent interest under Section 21, which declares that where an interest is to take effect only on the happening of a specified uncertain event, the person acquires a contingent interest, and it becomes vested only when that event happens.

The event itself — S dying without children — has two layers of uncertainty. First, it is uncertain whether S will die before or after D. Second, it is uncertain whether S will leave children or not. Both these uncertainties must resolve in D's favour before her interest can ever vest. Section 23 adds a further dimension: since no time is specified for this event to occur, D's contingent interest will fail unless the event happens concurrently with or before S's death. During S's lifetime, D holds what can be best described as a "springing" interest — a hope backed by law, transferable but not heritable. As the Privy Council observed in MA Yait v. Official Assignee (AIR 1930 PC 17), a contingent interest is something far more substantial than a mere spes successionis (a bare hope of succession); it is a recognised form of property that can be transferred and dealt with.

The Critical Doctrine: Conditions Subsequent Are Construed Strictly

One principle that protects S from easy divestiture deserves special mention. Section 29 of the Act, read with the commentary of the courts, insists that conditions subsequent which are intended to defeat vested interests must be strictly fulfilled. The law does not favour the divesting of an estate once vested. If there is any ambiguity in the defeasance clause, it will be resolved in favour of the vested interest. It is significant, therefore, that the gift over in favour of D uses the phrase "dies without children" — a phrase requiring that S should not have left surviving children at the time of his death. If S had children who predeceased him, the question of construction arises whether the condition is fulfilled. Courts have generally construed such phrases narrowly, in the sense most favourable to the vested interest, as illustrated by the position discussed in Re Cobbold, Cobbold v. Lawton (1903 2 Ch 299).

If the Defeasance Condition Is Void

It is worth noting what happens if the condition "dies without children" were to be held invalid for any reason. Section 30 of the Act provides that if the ulterior disposition is not valid, the prior disposition is not affected. S's vested interest would then become an absolute, indefeasible one, entirely freed from the condition. D would receive nothing. This reinforces the general principle that the validity of a subsequent gift over can never cast doubt on the prior vested interest.

To state the position with clarity: S holds a vested interest liable to be divested — a full ownership that is already operative but which will be transferred to D if S dies without children. D, meanwhile, holds a contingent interest — a present, legally recognised but unmatured right that will crystallise into ownership only upon the happening of the stipulated contingency. Both interests co-exist simultaneously in the same property: S enjoys the property fully while D watches and waits, her interest transferable but fragile, protected by law yet wholly dependent on the turn of events that life chooses to take.