How have the courts interpreted the principles of insurance in the context of an under-written policy?

In the case of Carter v. Boehm, 97 E.R. 1162, Lord Mansfield, at p. 1164, set out certain principles of insurance as follows: “. . . Insurance is a contract upon speculation. “The special facts, upon which the contingent chance is to be computed, lie most commonly in the knowledge of the insured only: the under-writer trusts to his representation, and proceeds upon confidence that he does not keep back any circumstance in his knowledge, to mislead the under-writer into a belief that the circumstance does not exist, and to induce him to estimate the risque, as if it did not exist. “The keeping back such circumstance is a fraud, and therefore the policy is void. Although the suppression should happen through mistake, without any fraudulent intention; yet still the under-writer is deceived, and the policy is void; because the risque run is really different from the risque understood and intended to be run, at the time of the agreement.” And then at p. 1165 Lord Mansfield went on to say: “The reason of the rule which obliges parties to disclose, is to prevent fraud, and to encourage good faith. It is adapted to such facts as vary the nature of the contract; which one privately knows, and the other is ignorant of, and has no reason to suspect. “The question therefore must always be ‘whether, there was, under all the circumstances at the time the policy was under-written, a fair representation; or a concealment; fraudulent, if designed; or, though not designed, varying materially the object of the policy, and changing the risque understood to be run.’”