Philosophy in its old form could exist only in the absence of engineering, but with engineering in existence and daily more active and far reaching, the old verbalistic philosophy and metaphysics have lost their reason to exist. They were no more able to understand the “production” of the universe and life than they are now able to understand or grapple with “production” as a means to provide a happier existence for humanity. They failed because their venerated method of “speculation” can not _produce_, and its place must be taken by mathematical thinking. Mathematical reasoning is displacing metaphysical reasoning. Engineering is driving verbalistic philosophy out of existence and humanity gains decidedly thereby. Only a few parasites and “speculators” will mourn the disappearance of their old companion “speculation.” The world of producers—the predominating majority of human beings—will welcome a philosophy of ordered thought and production. The scientists, all of them, have their duties no doubt, but they do not fully use their education if they do not try to broaden their sense of responsibility toward all mankind instead of closing themselves up in a narrow specialization where they find their pleasure. Neither engineers nor other scientific men have any right to prefer their own personal peace to the happiness of mankind; their place and their duty are in the front line of struggling humanity, not in the unperturbed ranks of those who keep themselves aloof from life. If they are indifferent, or discouraged because they feel or think that they know that the situation is hopeless, it may be proved that undue pessimism is as dangerous a “religion” as any other blind creed. Indeed there is very little difference in kind between the medieval fanaticism of the “holy inquisition,” and modern intolerance toward new ideas. All kinds of intellect must get together, for as long as we presuppose the situation to be hopeless, the situation will indeed be hopeless. The spirit of Human Engineering does not know the word “hopeless;” for engineers know that wrong methods are alone responsible for disastrous results, and that every situation can be successfully handled by the use of proper means. The task of engineering science is not only to know but to know how. Most of the scientists and engineers do not yet realize that their united judgment would be invincible; no system or class would care to disregard it. Their knowledge is the very force which makes the life of humanity pulsate. If the scientists and the engineers have had no common base upon which to unite, a common base must be provided. To-day the pressure of life is such that we cannot go forward without their coordinating guidance. But first there must be the desire to act. One aim of this book is to furnish the required stimulus by showing that Human Engineering will rescue us from the tangle of private opinions and enable us to deal with all the problems of life and human society upon