There is absolutely no evidence looking either way, and there never can be any such evidence. To his view and to all the others one may easily find objections.
The belief that communication with disembodied souls is wicked is a mere superstition derived from the ancient Jewish laws against witchcraft. With them, as with all primitive peoples, a witch was one who, like Glendower, could call spirits from the vasty deep, and the reason for discouraging the practise is obvious; it set up a dangerous competition with the regular priesthood, and cut off their revenues.
The Jewish priests had a prescribed orthodox method of consulting spirits, which contributed handsomely to their income, and it was scarcely to be expected that they would tolerate the piratical competition of hideous old women like the Witch of Endor.
Hence that command in the law of Moses, "Thou shalt not suffer a witch to live," which has been the cause of so much cruelty and bloodshed.
Science and Experience.
When science says a thing cannot be done, experience proves that she speaks prematurely almost always. We may as yet have no evidence of the reality of a future life, but that by no means demonstrates that we never shall have such evidence.
A century ago we had no evidence of the X-rays, of the telephone, of the new theory of non-atomic matter. That men have been trying from the beginning of time to demonstrate another existence and have always failed is of no significance. Perhaps they have not tried in the right way.
The objection that most of the things purporting to be said and done by spirits are absurd or trivial has no weight. The only way to find out how a spirit will act under given conditions is to place him under those conditions and watch the results.
What seems absurd to us may not seem so to him. If he exists at all, his norms of worth may be, and probably are, very different from ours. According to the valuations of the spirit world, rapping on a table may be as exalted a function as heading an army is with us.
How silly it was for Galvani to make a frog's leg twitch with his bits of zinc and copper! Yet something has come of it. How trifling a thing was the fall of Newton's apple! Yet he could see in it the revolutions of the stars.