Is the explanation difficult? It does not seem to me so. For it is simply this. To believe and accept any matter it is not sufficient that there be enough evidence, the subject itself must appeal to you, must ring true, must be good to be believed. But with ghosts to most of us it is the reverse. That our friends and those we love should after death behave as ghosts behave, should be silly, unreasonable, drivelling in their ways, imbecile in their performances, should in fact act as if the next world was a ghostly lunatic asylum, is not attractive but the reverse. For a murdered man's spirit to go fooling about scaring innocent people into fits, and unable to say right out that he wants his body buried, strikes the ordinary man as sheer idiocy. And therefore men laugh and jeer. People who see ghosts may believe them; no one else will do so. Because they are not worthy of belief. If these be indeed ghosts, and they act as ghost-seers say, it is a deplorable, a most deplorable thing. And if it is a choice of imbecilities, we would prefer to believe in the lunacy of ghost-seers rather than in that of the dead, our dead.
But it is not only in matters relating to religion as the idea of God, or to the supernatural as in ghosts, that we reject evidence. We can do so also in matters that have no connection with each. For why do we refuse to accept the sea serpent? Numbers of absolutely reliable men declare they have seen it. And yet we laugh, or at best we say, "They were mistaken, it was a trail of seaweed."
All men who have lived to a certain age have learnt that there are certain facts, certain experiences not at all connected with the supernatural, which they dare not tell of for fear of being put down as inventors. They are curious coincidences, narrow escapes, shooting adventures, and so on. They have happened to us all. Who has not heard the tale of the general at a dinner party who related some such incident that had occurred to himself, and was surprised to see amusement and disbelief depicted on the faces of all around him. "You do not believe me," he said stiffly, "but my friend opposite was with me at the time and saw it too." But the friend refused with a laugh to bear witness, and the conversation changed. "General," explained the friend subsequently to his irate companion, "I know, of course, all you said was true. But what would you have? If fifty men swore to it no one would believe them. They would only have put me down as a liar too."
Just as the old woman was ready to accept her travelled son's yarns of rivers of milk and islands of cheese; but when he deviated into the truth she stopped. "Na, Na!" she said, "that the anchor fetched up one of Pharaoh's chariot wheels out of the Red Sea, I can believe; but that fish fly! Na, Na! dinna come any o' your lies over yer mither."
They are old stories, but they illustrate my point. On some matters we are ready to believe at once, on others no amount of evidence will change our opinions.
Indeed, we are too apt to assume that reason is our great guide in life. To think before you act may be wise—sometimes. But if in matters of emergency you had to stop and think first, you would not succeed very well. The great men of action are those who act first and think afterwards, and sometimes they even do the latter badly. There is the story of a man who was going abroad to be a Chief Justice, and who was addressed by the Lord Chancellor in this way: "My friend, be careful where you are going. Your judgments will be nearly always right, but beware of giving your reasons, for they will almost invariably be wrong." There are many such men.
What, then, is religious proof? If it is not founded on evidence that all can accept, on what is it founded? Why do men believe their own religion and accept the evidence of it as irrefragable, while scornfully rejecting that in favour of other religions?
The answer, I think, is this.
If you will take two violins and will tune them together, and if while someone plays ever so lightly on one you will bend your ear to the other, you will hear faintly but clearly repeated from its strings the melody of the first. For they are in harmony. But if they are not, then there will be no echo, play you never so loudly.
And so it is in matters of religion. If you are in harmony with any thought there will come the echo in your heart's strings, and you will know that it is true. But if you are not in harmony, then no matter how loudly the evidence be sounded there will be no echo there. All these ideas on which religions are built are instincts. They are of the heart, never of the head. Reason affects them not at all. These instincts are not the same with all. They vary, and so the religions that are based on them vary. They have nothing to do with reason, and therefore those of one religion cannot understand another. And they are not fixed; for the belief in the Unity of God only evolved, after many thousands of years, quite recently, and the belief in ghosts, universal among earlier people and now among the half-civilized, lingers with us only as a subject for amusement. There is no "evidence" in religion; you either believe or you don't.