But an election once made by the Society and communicated to the assured is final. If an intention to disaffirm is thus evinced, the insurance is at an end, and its revival or reinstatement involves a new contract. On the other hand, if, after default, an intention to affirm the contract of insurance notwithstanding the default is communicated to him, then, although he remains liable to pay the premium, the insurance cannot be terminated unless and until he commits a new default. No doubt it would be possible to regard the issue of the bonus certificates as a sufficient indication of an intention to affirm the insurance, notwithstanding the default for so long a time in the payment of the premiums. But the two letters or notices to the assured from the Society, relating to the premiums due respectively on 1st August and 1st November 1930, express an intention to treat the policy as avoided by the non-payment of those premiums. The expression in the notice itself - "it is necessary that an application for reinstatement be made" - would itself suffice to show that the policy was regarded as otherwise at an end. But any doubt is removed by the recital in the accompanying form that the policy had lapsed. It is needless to inquire what was the effect of the acceptance and retention of the sum paid for the overdue premium which became payable on 1st August 1930; for the premium due on 1st November 1930 was never paid, notwithstanding the similar communication made in reference thereto. The intention to avoid the policy thus communicated was confirmed by the interview of the agent, whose evidence apparently was accepted by Crisp J. In these circumstances a final election to disaffirm was made which the subsequent issue of the bonus certificates could not affect. After 31st December 1930 the policy was no longer on foot. The appellant, therefore, cannot recover unless he is able to make out an estoppel precluding the Society from asserting that the policy had ceased to be in force before the death of the assured. To establish such an estoppel, it is necessary upon the facts of this case to show as a first step that as a result of the bonus certificates the deceased believed that his life remained insured by the policy. However ignorant and ill-informed he may have been, it is not easy to believe that he could regard his failure to pay no less than fourteen quarterly premiums as consistent with the continuance of the cover. This difficulty is increased by the evidence of the agent and the contents of the two notices, but, perhaps, having regard to the finding of Crisp J., it should be assumed that the repeated receipt of the bonus certificates overcame these considerations, and he was led to suppose that the policy remained in force. But, even so, yet another element is required to make out the estoppel. The reason for precluding a party from relying upon an actual state of affairs as the foundation of his rights lies in the injustice of permitting him to depart from some contrary assumption if another party has based his conduct upon it. The injustice of allowing him to disregard the assumption must arise from the circumstances attending its adoption by the other party. There are well recognized grounds for compelling adherence to such an assumption (cf. Thompson v. Palmer[3]). One such ground is that the assumption has been made because a belief in its correctness has been induced by the representation or the conduct of the party seeking to depart from it. But what makes it unjust to permit the departure from an assumption so induced is that, were it permitted, the party so induced would through making the assumption find himself in a position occasioning material detriment to himself. Without this element there is no estoppel. It must appear that upon the faith of his belief by act or omission he has placed himself in a position which, if his belief proved incorrect, would be productive of loss. In the present case complete inaction on his part is all that can be relied upon. He took no steps towards reviving his policy with the respondent society, and no steps towards obtaining any form of life assurance elsewhere. If it appeared that his supposed belief was a contributing cause of this inaction, sufficient connection between the assumption and the position of detriment would be established. Where inaction is the natural consequence of the assumption, the prima facie inference may be drawn in favour of the causal connection. But, according to the common course of affairs, a young unmarried man working on his father's orchard is not found insuring his life in the absence of some special reason, unless as a result of a canvasser's persuasion. In the present case the deceased, according to the learned Judge's finding, decided not to keep up his life policy. He expressed that determination emphatically to the agent. There is no reason to suppose that his belief, if it existed, that his policy was still on foot contributed in any way to his failure to obtain insurance upon his life. Everything points to the cost of insurance as the cause of that failure. His condition in life was such as to cause him to prefer to be without insurance rather than to incur the necessary periodical expenditure. Any general presumptive connection between inaction and a belief in a state of facts must depend upon probabilities which arise from the common course of affairs, and accordingly must be governed by circumstances. In the circumstances of the present case there is nothing to support an inference or presumption that the deceased's belief contributed to his dying uninsured.