As is so frequently the case with historical developments, it seems as though the actual implications of technology, that is, of the replacement of tools and implements with machinery, have come to light only in its last stage, with the advent of automation. For our purposes it may be useful to recall, however briefly, the main stages of modern technology's development since the beginning of the modern age. The first stage, the invention of the steam engine, which led into the industrial revolution, was still characterized by an imitation of natural processes and the use of natural forces for human purposes, which did not differ in principle from the old use of water and wind power. Not the principle of the steam engine was new but rather the discovery and use of the coal mines to feed it. The natural machine tools of this early stage reflect this imitation of naturally known processes; they too, imitate and put to more powerful use the natural activities of the human hand. But today we are told that "the greatest pitfall to avoid is the assumption that the design aim is reproduction of the hand movements of the operator or laborer"
The next stage is chiefly characterized by the use of electricity, and, indeed, electricity still determines the present stage of technical development. This stage can no longer be described in terms of gigantic enlargement and continuation of the old arts and crafts, and it is only to this world that the categories of homo faber, to whom every instrument is a means to achieve a prescribed end, no longer apply. For here we no longer use material as nature yields it to us, killing natural processes or interrupting or imitating them. In all these instances, we changed and denaturalized nature for our own worldly ends, so that the human world or artifice on one hand and nature on the other remained two distinctly separate entities. Today we have begun to "create", as it were, that is, to unchain natural processes of our own which would never have happened without us, and instead of carefully surrounding the human artifice with defenses against nature's elementary forces, keeping them as far as possible outside the man-made world, we have channeled these forces, along with their elementary power, into the world itself. The result has been a veritable revolution in the concept of fabrication; manufacturing, which wlways had been "a series of separate steps," has become "a continuous process," the process of the conveyor belt and the assembly line.