The training of a stock trader is like a medical education. The physician has to spend long years learning anatomy, physiology, materia medica and collateral subjects by the dozen. He learns the theory and then proceeds to devote his life to the practice. He observes and classifies all sorts of pathological phenomena. He learns to diagnose. If his diagnosis is correct--and that depends upon the accuracy of his observation--he ought to do pretty well in his prognosis, always keeping in mind, of course, that human fallibility and the utterly unforeseen will keep him from scoring 100 per cent of bull’s-eyes. And then, as he gains in experience, he learns not only to do the right thing but to do it instantly, so that many people will think he does it instinctively. It really isn’t automatism. It is that he has diagnosed the case according to his observations of such cases during a period of many years; and, naturally, after he has diagnosed it, he can only treat it in the way that experience has taught him is the proper treatment. You can transmit knowledge--that is, your particular collection of card-indexed facts--but not your experience. _A man may know what to do and lose money--if he doesn’t do it quickly enough._ Observation, experience, memory and mathematics--these are what the successful trader must depend on. He must not only observe accurately but remember at all times what he has observed. He cannot bet on the unreasonable or on the unexpected, however strong his personal convictions may be about man’s unreasonableness or however certain he may feel that the unexpected happens very frequently. He must bet always on probabilities--that is, try to anticipate them. Years of practice at the game, of constant study, of always remembering, enable the trader to act on the instant when the unexpected happens as well as when the expected comes to pass. A man can have great mathematical ability and an unusual power of accurate observation and yet fail in speculation unless he also possesses _the experience and the memory_. And then, like the physician who keeps up with the advances of science, _the wise trader never ceases to study general conditions, to keep track of developments everywhere that are likely to affect or influence the course of the various markets_. After years at the game it becomes a habit to keep posted. He acts almost automatically. He requires the invaluable professional attitude and that enables him to beat the game--at times! This difference between the professional and the amateur or occasional trader cannot be overemphasised. I find, for instance, that memory and mathematics help me very much. Wall Street makes its money on a mathematical basis. I mean, _it makes its money by dealing with facts and figures_.