"I can't listen to abstract theorising," he said. "Have you any fresh concrete evidence?"
"Sir, everything depends on our getting down to the root of the matter. What percentage of average evidence should you think is thorough, plain, simple, unvarnished fact, 'the truth, the whole truth, and nothing but the truth'?"
"Fifty?" said the Minister, humouring him a little.
"Not five. I say nothing of lapses of memory, of inborn defects of observational power—though the suspiciously precise recollection of dates and events possessed by ordinary witnesses in important trials taking place years after the occurrences involved, is one of the most amazing things in the curiosities of modern jurisprudence. I defy you, sir, to tell me what you had for dinner last Monday, or what exactly you were saying and doing at five o'clock last Tuesday afternoon. Nobody whose life does not run in mechanical grooves can do anything of the sort; unless, of course, the facts have been very impressive. But this by the way. The great obstacle to veracious observation is the element of prepossession in all vision. Has it ever struck you, sir, that we never see any one more than once, if that? The first time we meet a man we may possibly see him as he is; the second time our vision is coloured and modified by the memory of the first. Do our friends appear to us as they appear to strangers? Do our rooms, our furniture, our pipes strike our eye as they would strike the eye of an outsider, looking on them for the first time? Can a mother see her babe's ugliness, or a lover his mistress's shortcomings, though they stare everybody else in the face? Can we see ourselves as others see us? No; habit, prepossession changes all. The mind is a large factor of every so-called external fact. The eye sees, sometimes, what it wishes to see, more often what it expects to see. You follow me, sir?"
The Home Secretary nodded his head less impatiently. He was beginning to be interested. The hubbub from without broke faintly upon their ears.
"To give you a definite example. Mr. Wimp says that when I burst open the door of Mr. Constant's room on the morning of December 4th, and saw that the staple of the bolt had been wrested by the pin from the lintel, I jumped at once to the conclusion that I had broken the bolt. Now I admit that this was so, only in things like this you do not seem to conclude, you jump so fast that you see, or seem to. On the other hand, when you see a standing ring of fire produced by whirling a burning stick, you do not believe in its continuous existence. It is the same when witnessing a legerdemain performance. Seeing is not always believing, despite the proverb; but believing is often seeing. It is not to the point that in that little matter of the door Wimp was as hopelessly and incurably wrong as he has been in everything all along. The door was securely bolted. Still I confess that I should have seen that I had broken the bolt in forcing the door, even if it had been broken beforehand. Never once since December 4th did this possibility occur to me, till Wimp with perverted ingenuity suggested it. If this is the case with a trained observer, one moreover fully conscious of this ineradicable tendency of the human mind, how must it be with an untrained observer?"
"Come to the point, come to the point," said the Home Secretary, putting out his hand as if it itched to touch the bell on the writing-table.
"Such as," went on Grodman, imperturbably, "such as—Mrs. Drabdump. That worthy person is unable, by repeated violent knocking, to arouse her lodger who yet desires to be aroused; she becomes alarmed, she rushes across to get my assistance; I burst open the door—what do you think the good lady expected to see?"
"Mr. Constant murdered, I suppose," murmured the Home Secretary, wonderingly.
"Exactly. And so she saw it. And what should you think was the condition of Arthur Constant when the door yielded to my violent exertions and flew open?"