«The philosophic burden of proof lies upon a person making scientifically unfalsifiable claims rather than shifting the burden of proof to others, specifically in the case of religion.»
Is There a God? by Bertrand Russell
The question whether there is a God is one which is decided on very different grounds by different communities and different individuals. The immense majority of mankind accept the prevailing opinion of their own community. In the earliest times of which we have definite history everybody believed in many gods. It was the Jews who first believed in only one. The first commandment, when it was new, was very difficult to obey because the Jews had believed that Baal and Ashtaroth and Dagon and Moloch and the rest were real gods but were wicked because they helped the enemies of the Jews. The step from a belief that these gods were wicked to the belief that they did not exist was a difficult one. There was a time, namely that of Antiochus IV, when a vigorous attempt was made to Hellenize the Jews. Antiochus decreed that they should eat pork, abandon circumcision, and take baths. Most of the Jews in Jerusalem submitted, but in country places resistance was more stubborn and under the leadership of the Maccabees the Jews at last established their right to their peculiar tenets and customs. Monotheism, which at the beginning of the Antiochan persecution had been the creed of only part of one very small nation, was adopted by Christianity and later by Islam, and so became dominant throughout the whole of the world west of India. From India eastward, it had no success: Hinduism had many gods; Buddhism in its primitive form had none; and Confucianism had none from the eleventh century onward. But, if the truth of a religion is to be judged by its worldly success, the argument in favor of monotheism is a very strong one, since it possessed the largest armies, the largest navies, and the greatest accumulation of wealth. In our own day this argument is growing less decisive. It is true that the un-Christian menace of Japan was defeated. But the Christian is now faced with the menace of atheistic Muscovite hordes, and it is not so certain as one could wish that atomic bombs will provide a conclusive argument on the side of theism.
But let us abandon this political and geographical way of considering religions, which has been increasingly rejected by thinking people ever since the time of the ancient Greeks. Ever since that time there have been men who were not content to accept passively the religious opinions of their neighbors, but endeavoured to consider what reason and philosophy might have to say about the matter. In the commercial cities of Ionia, where philosophy was invented, there were free-thinkers in the sixth century B.C. Compared to modern free-thinkers they had an easy task, because the Olympian gods, however charming to poetic fancy, were hardly such as could be defended by the metaphysical use of the unaided reason. They were met popularly by Orphism (to which Christianity owes much) and, philosophically, by Plato, from whom the Greeks derived a philosophical monotheism very different from the political and nationalistic monotheism of the Jews. When the Greek world became converted to Christianity it combined the new creed with Platonic metaphysics and so gave birth to theology. Catholic theologians, from the time of Saint Augustine to the present day, have believed that the existence of one God could be proved by the unaided reason. Their arguments were put into final form by Saint Thomas Aquinas in the thirteenth century. When modern philosophy began in the seventeenth century, Descartes and Leibniz took over the old arguments somewhat polished up, and, owing largely to their efforts, piety remained intellectually respectable. But Locke, although himself a completely convinced Christian, undermined the theoretical basis of the old arguments, and many of his followers, especially in France, became Atheists. I will not attempt to set forth in all their subtlety the philosophical arguments for the existence of God. There is, I think, only one of them which still has weight with philosophers, that is the argument of the First Cause. This argument maintains that, since everything that happens has a cause, there must be a First Cause from which the whole series starts. The argument suffers, however, from the same defect as that of the elephant and the tortoise. It is said (I do not know with what truth) that a certain Hindu thinker believed the earth to rest upon an elephant. When asked what the elephant rested upon, he replied that it rested upon a tortoise. When asked what the tortoise rested upon, he said, «I am tired of this. Suppose we change the subject.» This illustrates the unsatisfactory character of the First-Cause argument. Nevertheless, you will find it in some ultra-modern treatises on physics, which contend that physical processes, traced backward in time, show that there must have been a sudden beginning and infer that this was due to divine Creation. They carefully abstain from attempts to show that this hypothesis makes matters more intelligible.