Happily, these circumstances are all to be found in the subject of NATURAL RELIGION. What truth so obvious, so certain, as the being of a God, which the most ignorant ages have acknowledged, for which the most refined geniuses have ambitiously striven to produce new proofs and arguments? What truth so important as this, which is the ground of all our hopes, the surest foundation of morality, the firmest support of society, and the only principle which ought never to be a moment absent from our thoughts and meditations? But, in treating of this obvious and important truth, what obscure questions occur concerning the nature of that Divine Being, his attributes, his decrees, his plan of providence? These have been always subjected to the disputations of men; concerning these human reason has not reached any certain determination. But these are topics so interesting, that we cannot restrain our restless inquiry with regard to them; though nothing but doubt, uncertainty and contradiction, have as yet been the result of our most accurate researches. This I had lately occasion to observe, while I passed, as usual, part of the summer season with Cleanthes, and was present at those conversations of his with Philo and Demea, of which I gave you lately some imperfect account. Your curiosity, you then told me, was so excited, that I must, of necessity, enter into a more exact detail of their reasonings, and display those various systems which they advanced with regard to so delicate a subject as that of natural religion. The remarkable contrast in their characters still farther raised your expectations; while you opposed the accurate philosophical turn of Cleanthes to the careless scepticism of Philo, or compared either of their dispositions with the rigid inflexible orthodoxy of Demea. My youth rendered me a mere auditor of their disputes; and that curiosity, natural to the early season of life, has so deeply imprinted in my memory the whole chain and connexion of their arguments, that, I hope, I shall not omit or confound any considerable part of them in the recital. PART I.