Evolution quotes: Quetelet on populations 12 Jan 201212 Jan 2012 Populations arise imperceptibly; it is only when they have reached a certain degree of development that we begin to think of their existence. This increase is more or less rapid, and it proceeds either from an excess of births over deaths, or from immigrations, or both. In general, it is a mark of wellbeing, and of the means of existence being superior to the wants of the actual population. If we approach or exceed this limit, the state of increase soon stops, or a contrary condition may take place. It is then interesting to examine how different countries are populated, what are the means of subsistence and the rate of increase of the people, and to assign the limit which they may reach without danger. After that, the consideration is, to know the composition of the population, and if the constituent elements are advantageously distributed, and contribute, in a more or less efficient manner, to the well-being of the whole. But it would be proper first to take the questions or highest moment, and to establish, in a summary and clear manner, the ideas on population promulgated by the most distinguished economists. It appears incontestible, that population would increase in a geometrical ratio, if no obstacle were presented to its development. The means of subsistence are not developed so rapidly; and, according to Malthus, in the most favourable circumstances for industry, they can never increase quicker than in an arithmetical ratio. The obstacle to population, then, is the want of food, proceeding from the difference of ratio which these two quantities follow in their respective increases. When a population, in its development, has arrived at the level of its means of subsistence, it ought to stop at this limit, from human foresight; or if it have the misfortune to overleap this limit, it must be forcibly brought back by an excess of mortality. The obstacles to population, therefore, may be arranged under two heads—the one acts by preventing the growth of population, and the other by destroying it in proportion as it is formed. The sum of the first forms what may be called the privative obstacle, that of the second the destructive obstacle. Mr Malthus has analysed, with great sagacity, the principal obstacles to its increase which population has met with; he has determined. with no less credit, the limit which it cannot pass without being exposed to the greatest danger. However, it may be necessary to remark, notwithstanding the researches of the English philosopher, and of the economists who have followed in his track, that the modus operandi of the obstacles has not been clearly made out. The law has not been established by virtue of which they operate: in a word, they have not afforded the means of carrying the theory of population into the domains of mathematical science, to which it seems particularly to belong. Hence it results, that the discussion of this delicate point has not been completed at the present day, and the dangers attending society have perhaps been exaggerated, from not finding sufficient security in the action of the obstacles against an evil, the dreadful rapidity of which followed a geometrical progression. To endeavour to fill up so important a lacuna, I have made numerous researches, the details of which it will be superfluous here to present; and an attentive examination of the state of the question has proved to me, that the theory of population may be reduced to the two following principles, which I consider will hereafter serve as fundamental principles in the analysis of the development of population, and of the causes which influence it. Population tends to increase in a geometrical ratio. The resistance, or sum of the obstacles to its development, is, all things being equal, as the square of the rapidity with which it tends to increase. M Adolphe Quetelet, A treatise on man and the development of his faculties, Edinburgh, William and Robert Chambers, 1842 [1835], page 48f. Evolution History Quotes
History Plato on the origin of the gods 15 Nov 2009 As for the other spiritual beings [daimones], it is beyond our task to know and speak of how they came to be. We should accept on faith the assertions of those figures of the past who claimed to be the offspring of gods. They must surely have been well informed… Read More
Administrative News from Ediacara 27 Oct 2008 The Ediacaran period is the era between around 635Mybp and 540Mybp, just before the Cambrian. You pronounce it “ed-ee-ack-a-ran”. It is also the name of a new blog by the inimitable Chris Nedin, erstwhile paleontologist who specialised in the Ediacaran fauna before joining the Dark Side (federal public service) in… Read More
Interesting. The French version in 1835 precedes Verhulst(1838) who usually gets credit for the corresponding equation. And they were both at Ghent at around the same time. Do you know anything about their personal interactions?
Absolutely nothing. I’d go first to Gigerenzer’s Empire of chance, but he doesn’t give much in the way of social stuff. Update: But see here. Apparently they worked together.