If, however, the constructive effort develops successfully the conception that the imagination made, and if the circumstances of time and place are all propitious, then the art of making fire at will is born, or Bonaparte's suggestion at Toulon is made, or the strains of Beethoven's music inspire the world, or the statue of Moses is carved, or the Immaculate Conception is pointed, or Hamlet is written, or the electric telegraph binds the peoples of the earth together.
The inventor in mechanics, the sculptor, the painter, the novelist and the poet embody their creations in material forms that are enduring and definite, and constitute evidences of their work, which sometimes endure throughout long periods. The architect and the constructing engineer are able similarly to produce lasting and useful monuments to their skill; but it can hardly be declared that their work is characterized by quite so much of originality and invention, because of the restrictions by which the practice of their arts is bound. It is, in fact, hard to conceive of a bridge very different in principle or design from bridges that had been built before; and while it is not difficult to conceive of an engine different in principle and design from previous ones, yet we realize that the points of novelty in such an engine would be attributable more to invention than to engineering. This is because the arts of engineering and architecture rest on principles that have long since been proved to be correct, and on practices that are the results of long experience; whereas one of the main characteristics of invention is novelty.
It is true that many of the most important inventions have been made by engineers; but this has been because some engineers, like Ericsson, have been inventors also. But it is also true that only a small proportion of the engineers have made original inventions; and it is equally true that many inventions have failed—or have been slow in achieving success—because of lack of engineering skill in construction or design. These facts show that the work of the inventor is very different from that of the engineer, and that the inventor and the engineer are very different people, though an engineer and an inventor sometimes live together inside of the same skin. In fact, it is by a combination of inventive genius and engineering talent in one man that the greatest results in invention have been achieved; though great results have often followed the intimate cooperation of an inventor and an engineer, the two being separate men.
It is in the latter way that important advances have usually been made; and it is somewhat analogous to the way in which authors and publishers, actors and managers, promoters and capitalists cooperate.
But while the individuals whose inventions have taken the form of new creations, such as novel machines and books and paintings, have received the clearest recognition as men of genius, may not the inventive faculty be needed in other fields and be required in other kinds of work? If an instrument is produced by the joint exercise of imagination and constructive talent, is not every puzzle worked out, and every problem solved, and every constructive work accomplished by the similar exercise of those same faculties?
It may seem obvious that this question should be answered in the negative, and so it unquestionably should be. But there always has been much cloudiness as to what constitutes invention in our own minds; and it must be admitted that the dividing line is not immediately obvious between invention and the art of meeting difficulties with resourcefulness, or between invention and the act of solving any of the perplexing riddles of our daily lives.
It may be declared with confidence, however, that the difference between invention and any one of these other acts is that, while invention ends in performing such acts, it begins with an exercise of the imagination. A man who designs an engine to fulfil a stated purpose, who solves any problem whatever that is presented to him from outside, simply accomplishes a task that is given to him to accomplish; whereas, while the inventor accomplishes a similar task, he does it as a second step in a task that was not given him to accomplish, but that he himself had pictured to himself. The act of inventing consists of three separate acts—the act of conceiving, the act of developing, and the act of producing. Of these three acts, that of conceiving is obviously not only the first, but also the most important, distinctive and unusual.
For every real invention, there have been countless constructive acts. In the invention of the bow and arrow, the conception was probably instantaneous and unbidden. The subsequent work of developing the conception into material and practical shape was probably one of long duration, consisting of many acts, accompanied with many difficulties and disappointments, and accomplished finally in the face of much active and passive opposition.
*****
The Old Stone Age gradually developed into the New Stone Age at different times in different localities, as successive improvements in implements were made. The New Stone Age was distinguished from its predecessor mainly by the fact that the principal weapons and utensils were formed into regular shapes, polished into smoothness, and in many cases ground to sharp points and keen cutting edges. These improvements made the implements more effective both as weapons and as utensils, by facilitating not only cutting but penetration.
How much invention was needed to make these improvements, it is not easy to decide; but probably only a little was required, and that of an order not very original or high; for the improvements were rather in detail than principle. Perhaps their character can be best indicated by saying that they were improvements, rather than inventions of a basic kind.
It may here be pointed out that the act of improving upon an invention already existing may be almost wholly a constructive act, performed on a visible and tangible material object, and not on a picture made by the imagination on the mind. In such a case, the act of improving belongs rather in the category of engineering than of invention, for the reason that it involves only a slight use of the imagination. It may also be pointed out, however, that a mere improvement may be, and sometimes has been an invention of the highest order. As a rule, of course, basic inventions have been the most brilliant and also the most important.
But it was not only by polished instruments of stone and bone that the New Stone Age was characterized; for we find in the records which our ancestors unintentionally left us, many evidences that they had invented the arts of making pottery, of spinning and weaving, and of constructing houses of a simple kind. This Age was characterized by many improvements besides those relating to articles of stone, and was a period far in advance of its predecessor on the march to civilization. It was marked by the domestication of animals and plants, the tilling of the soil, and a gradual change from a purely savage and nomadic mode of life. This change was first to a pastoral life, in which men lived in fixed habitations and tended their flocks; thence to an agricultural life, in which men cultivated the ground over large areas and grew crops of cereals and vegetables; and then to a still more settled existence, in which men congregated in villages and towns. Certainly, the race had taken the first steps, and had started on the path which it has since pursued.
In order to make the start and to proceed afterwards in the line begun, many physical, mental and spiritual attributes were needed and employed, that mere brutes did not possess, and because of which the civilization of the Old Stone Age had been begun and gradually developed. Of these faculties, those principally characteristic seem to have been mental; and among those faculties, invention, reason, construction and memory seem to have been the most important. It would be unreasonable to declare any one of those faculties to have been more important than the others; but it can hardly be denied that the first steps in the march of progress should be credited to invention. Clearly, it was the weapons and utensils of the Old Stone Age that made possible the subduing and subsequent domestication of certain animals, such as the horse, the cow, the dog, the sheep and the goat.
It may be pointed out, in passing, that many animals have not been domesticated even at this late day—such