It is important to remember that in order to have an organized system of philosophical instruction, teachers needed to have a surplus of time and energy, as well as a meeting center for an audience. With the growing communities that emerged in the eighth century, wealthier landowners and Greek citizens enjoyed these conditions.
In Ancient Greece, warfare was an important characteristic in the development of the polis (or city-state). Beginning with Herodotus, who is credited as the first Greek historian, war was the primary subject given attention by both historians and philosophers. In may ways, warfare and philosophy were interchangable, just as religion and everyday life were interchangable during the middle ages.
Warfare was almost exclusively the practice of aristocracies. Their warrior-ethic was a combination of courage, loyalty, and of course strength.