But it so happens that everything on this planet is, ultimately, irrational; there is not, and cannot be, any reason for the causal connexion of things, if only because our use of the word reason already implies the idea of causal connexion. But, even if we avoid this fundamental difficulty, Hume said that causal connexion was not merely unprovable, but unthinkable; and, in shallower waters still, one cannot assign a true reason why water should flow down hill, or sugar taste sweet in the mouth. Attempts to explain these simple matters always progress into a learned lucidity, and on further analysis retire to a remote stronghold where every thing is irrational and unthinkable.If you cut off a man's head, he dies. Why? Because it kills him. That is really the whole answer. Learned excursions into anatomy and physiology only beg the question; it does not explain why the heart is necessary to life to say that it is a vital organ. Yet that is exactly what is done, the trick that is played on every inquiring mind. Why cannot I see in the dark? Because light is necessary to sight. No confusion of that issue by talk of rods and cones, and optical centres, and foci, and lenses, and vibrations is very different to Edwin Arthwait's treatment of the long-suffering English language.Knowledge is really confined to experience. The laws of Nature are, as Kant said, the laws of our minds, and, as Huxley said, the generalization of observed facts.It is, therefore, no argument against ceremonial magic to say that it is absurd to try to raise a thunderstorm by beating a drum; it is not even fair to say that you have tried the experiment, found it would not work, and so perceived it to be impossible. You might as well claim that, as you had taken paint and canvas, and not produced a Rembrandt, it was evident that the pictures attributed to his painting were really produced in quite a different way.You do not see why the skull of a parricide should help you to raise a dead man, as you do not see why the mercury in a thermometer should rise and fall, though you elaborately pretend that you do; and you could not raise a dead man by the aid of the skull of a parricide, just as you could not play the violin like Kreisler; though in the latter case you might modestly add that you thought you could learn.This is not the special pleading of a professed magician; it boils down to the advice not to judge subjects of which you are perfectly ignorant, and is to be found, stated in clearer and lovelier language, in the Essays of Thomas Henry Huxley.