Another evil, and one of the worst which arises from the separation of theoretical and practical knowledge, is the fact that a large number of persons, possessed of an inventive turn of mind and of considerable skill in the manual operations of practical mechanics, are destitute of that knowledge of scientific principles which is requisite to prevent their being misled by their own ingenuity. Such men too often spend their money, waste their lives, and it may be lose their reason in the vain pursuits of visionary inventions, of which a moderate amount of theoretical knowledge would be sufficient to demonstrate the fallacy ; and for want of such knowledge, many a man who might have been a useful and happy member of society, becomes a being than whom it would be hard to find anything more miserable.
The number of those unhappy persons — to judge from the patent-lists, and from some of the mechanical journals — must be much greater than is generally believed.

A scheme such as mine is gravely imperiled if it is opposed by "practical" people. Now "practical" people are as a rule nothing more than men sunk into the groove of daily routine, unable to emerge from a narrow circle of antiquated ideas. At the same time, their adverse opinion carries great weight, and can do considerable harm to a new project, at any rate until this new thing is sufficiently strong to throw the "practical" people and their mouldy notions to the winds.

The evil influence of the supposed inconsistency of theory and practice upon speculative science, although much less conspicuous than it was in the ancient and middle ages, is still occasionally to be traced. This it is which opposes the mutual communication of ideas between men of science and men of practice, and which leads scientific men sometimes to employ, on problems that can only be regarded as ingenious mathematical exercises, much time and mental exertion that would be better bestowed on questions having some connection with the arts, and sometimes to state the results of really important investigations on practical subjects in a form too abstruse for ordinary use; so that the benefit which might be derived from their application is for years lost to the public; and valuable practical principles which might have been anticipated by reasoning, are left to be discovered by slow and costly experience.

1. The first is simply not to try to be clever. Innovations have to be handled by ordinary human beings, if they are to attain any size and importance at all, by morons or near-morons. Incompetence, after all, is the only thing in abundant and never-failing supply. Anything too clever, whether in design or execution, is almost bound to fail.

plenty of instances of the persecution of inventors, even to quite a late date. It is impossible, of course, to say how many good things were lost to the world by the pig-headedness which discouraged new inventions. It is marvellous to think what progress single men made, who had to begin almost at the beginning, and learn for themselves what every intelligent boy or girl now finds ready for him in the Cyclopædia. It is very clear that the same beginnings were made again and again by some of the early inventors. Then, what they learned had been almost forgotten. There was no careful record of their experiments, or, if any, it was in one manuscript, and that was not accessible to people trying to follow in their steps.

It's always an imprudence to step between a man and the reflection of his own cleverness.

Weaknesses in men of genius are usually an exaggeration of their personal feeling; in the hands of feeble imitators they become the most flagrant blunders. Entire schools have been founded on misinterpretations of certain aspects of the masters. Lamentable mistakes have resulted from the thoughtless enthusiasm with which men have sought inspiration from the worst qualities of remarkable artists because they are unable to reproduce the sublime elements in their work.

For these kind of men that are so given up to the study of wisdom are generally most unfortunate, but chiefly in their children; Nature, it seems, so providently ordering it, lest this mischief of wisdom should spread further among mankind.

Crafty men condemn studies; Simple men admire them; And wise men use them: For they teach not their own use: but that is a wisdom without them, and above them, won by observation.