As a practice, induction is nothing but our old friend, the law of conditioned reflexes or of association. A child touches a knob that gives him an electric shock; after that, he avoids touching the knob. If he is old enough to speak he may state that the knob hurts when it is touched; he has made an induction based on a single instance. But the induction will exist as a bodily habit even if he is too young to speak, and it occurs equally among animals, provided they are not too low in the scale. The theories of induction in logic are what Freudians call a “rationalisation”; that is to say, they consist of reasons invented afterwards to prove that what we have been doing is sensible. It does not follow that they are bad reasons; in view of the fact that we and our ancestors have managed to exist since the origin of life, our behaviour and theirs must have been fairly sensible, even if we and they were unable to prove that it was. This, however, is not the point that concerns us at present. What concerns us at present is the fact that verbal induction is a late development of induction in behaviour, which is nothing more or less than the principle of “learned reactions”. This principle, as the reader will remember, states that, if a certain event calls out a certain response, and if another event is experienced just before it, or at the same moment, in time that other event will tend to call out the response which, originally, only the first event would call out. This applies both to muscles and to glands; it is because it applies to glands that words are capable of causing emotions. Moreover, we cannot set limits to the length of the chain of associations that may be established. If you hold an infant’s limbs, you call out a rage reaction; this appears to be an “unlearned reaction”. If you, and no one else, repeatedly hold an infant’s limbs, the mere sight of you will call out a rage reaction after a time. When the infant learns to talk your name may have the same effect. If, later, he learns that you are an optician, he may come to hate all opticians; this may lead him to hate Spinoza because he made spectacles, and thence he may come to hate metaphysicians and Jews. For doing so he will no doubt have the most admirable reasons, which will seem to him to be his real ones; he will never suspect the process of conditioning by which he has in fact arrived at his enthusiasm for the Ku Klux Klan. This is an example of conditioning in the emotional sphere; but it is rather in the muscular sphere that we must seek the origin of the practice of induction.