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 sense, education, and learning, as to secure us against all delusion in themselves; of such undoubted integrity as to place them beyond all suspicion of any design to deceive others; of such credit in the eyes of mankind as to have a great deal to lose in case of their being detected in any falsehood, and at the same time attesting facts performed in such a public manner as to render detection unavoidable—all which circumstances are requisite to give us a full assurance in the testimony of men.

In the Dialogues on Natural Religion which were not published till after his death (1776), Hume made an attack on the "argument from design," on which deists and Christians alike relied to prove the existence of a Deity. The argument is that the world presents clear marks of design, endless adaptation of means to ends, which can only be explained as due to the deliberate plan of a powerful intelligence. Hume disputes the inference on the ground that a mere intelligent being is not a sufficient cause to explain the effect. For the argument must be that the system of the material world demands as a cause a corresponding system of interconnected ideas; but such a mental system would demand an explanation of its existence just as much as the material world; and thus we find ourselves