| Sorites Paradox. The fallacy lies in the question, that a collection of sand is either individual grains aggregated, or a heap. One response is that "heap" describes not quantity but behaviour, or even more crucially, useful mental models. The old parable of grains of rice doubled on successive squares of a chessboard gives a useful visual image, here: http://all-funny.info/rice-chessboard-story I'd argue that the transition between "grains" and "heap" occurs somewhere between 16 and 128 grains, the 6th to 8th squares (2^5 to 2^7). Sixteen grains is still, mostly, individual grains. 128 grains is almost certainly a heap. In urban geography, urbanisations are virtually always classed by the log, usually base ten, of their population. This gives settlements of class 0 (one inhabitant) to about class 7.6 (roughly 40 millions of souls, greater Tokyo). Distribution nearly perfectly follows a power distribution -- frequency distribution is linear with the log size. Going back through human history, the first settlements we might have termed "cities" may well have been only a few hundreds of inhabitants, but they would have dominated their regions. Anthropologists typically identify Uruk as the first settlement recognised as a city. "Many ancient cities had only modest populations, often under 5,000 persons." https://www.ancient.eu/city/ A city is a permanent settlement of size and complexity which acts as a city. |