The existence of a leisure class and the want for change are two key societal factors necessary for technological innovation. There are surely other things that factor in, such as the availability of materials, relative usefulness, and supranational interactions among many others, but the most important for the evolution of technology are the creative minds provided by a leisured class and the lesser limits that are imposed by a society open to change.
A leisure class is any group of people, within a society, who do not labor for a living: either in the fields or in the market. Therefore, farmers, merchants, and artisans do not strictly qualify as existing within the leisure class; however they may make their own contributions to technological innovation given enough free time from their daily work. While aristocrats may fall within this sect in the strictest sense of the definition, since they do not labor in the fields or the market, their main focus is often times a labor of social duty; they spend much of their time, and money, being social and fulfilling their social obligations, either to the court or to other aristocrats. The scholars are the people of leisure that we are looking for. In Medieval Europe the scholar would be found below the royalty and aristocracy and above the artisans, merchants, and farmers in the social pyramid. At times the scholar performs the duties of the merchant, the artisan, and the aristocrat, in marketing his ideas and creating them, but the majority of his time would be spent as a philosopher, mathematician, engineer, or astronomer.
The scholar cannot exist without the existence of the other classes as his livelihood depends upon of the work of the others, but his work can often make the work of the other classes, at least of the lower classes, all that much simpler. What allows for the rise of the scholar is the abundance of food: a movement away from subsistence farming toward affluence farming, the excessive working the field for the purpose of wealth. "To feed them [citizens], the farmers, herdsmen, and fishermen had to produce more food than they themselves consumed... New and more productive farming practices went hand in hand with a radically new organization of society" (Headrick 18). The cultivation of more food than one need was not sufficient for the rise of the classed society. What was more important and seems to have coincided with the change in pastoral philosophy is the movement of people into large societies - civilizations. With so many more people with in a smaller area, it became less necessary for people to be skilled in all fields and now people could focus their time on a single practice. Where in the villages or tribes it was more efficient for just a single person to be the local blacksmith, tanner, weapon smith, and carpenter, and to sell his own wares, in the cities it was more efficient for that person to just focus his time and energy on blacksmithing, thereby increasing the skill of his trade, and use a third-party merchant to sell his wares for him. It is through the use of the various classes: the farmers for food, the artisan for wares, the merchant for obtaining the goods, and the aristocracy for wealth and power, that the scholarly, educated class is able to be sustained.
The second key factor in the advancing of technology is the want, by a society or culture, for change. Through the changing technologies a society can see benefit in efficiency and quality of life, though at times that change can be initially detrimental to the quality of life, as can be seen by the military advancements by the states of post-Roman Europe. Now an important distinction must be made between the need for a new technology and the want for it. Should there be no benefit to the state by the implementation of a newer or differing technology, there is neither the need nor the want for its use. This is not what should be understood as the meaning on not wanting change. The refusal for change is a denial of advancement based upon religious, cultural, or societal bases. The people of Japan, after having seen the decimation caused to the samurai culture by the development of gunpowder weaponry, virtually ceased all advances in weapons development. "The country [Japan] was practically cut off from contact with the outside world and saw no reason to keep up with technological changes occurring elsewhere" (Headrick 79). The empire of China, after having amassed a great naval force, chose to focus their development inward in defense from the Mongols to the north. The nation collapsed inward appropriating its resources not to the advancement of their military power, but to making what they already held that much more efficient (Headrick 72-73), especially in the area of agriculture and city defense. The Arabs, who once controlled a vast empire from Pakistan to Spain in the seventh and eighth centuries and "excelled in the sciences, especially mathematics, astronomy, and medicine" (Headrick 69) refused the great technology of the printing press on religious grounds for over two hundred years after its common availability, thereby limiting the spread of knowledge throughout their own empire (Headrick 85-87). Perhaps the most obvious example of a civilization representing the want for change can be found throughout post-Roman Europe where there no longer existed a single ruling power (Rome), but instead existed many small states. These states were at constant war with one another and from that came the need to constantly acquire newer better weaponry. When one group would become the greatest power, militarily, it behooved the rivals to strive for even greater technologies. The advances in blacksmithing, transportation, civil engineering, chemistry, astronomy, mathematics, and the maritime can all be directly attributed to the need for greater military power. There existed a want for change in technology throughout these warring states because there was a constant need for its evolution, or dire consequences would follow.
While there is no doubt that technology can advance without the benefit of a scholarly class of citizens or without the want for new technology, it does so at a much slower rate. Those groups that did focus their time and resources on technological innovation (i.e. Europe) are able to see the benefits of it most obviously in their rule over those who do not (i.e. East Asia, Middle East, and Africa). The military power that would be held by their colonial forces is derived from the constant evolution in their technology over the hundreds of years which preceded.