I have often commented in the past that the supposed scientific revolution is described in popular presentations as the astronomical revolution and the modernisation of physics with sometimes a bit of medicine tacked on to make it seem broader whereas in fact in the period between about 1400 and 1700 CE a very wide spectrum of academic disciplines went through a period of renewal or were created for the first time driven by the socio-economic and political pressures of the age. Today’s birthday boy John Graunt, born on the 24th April 1620, is credited with creating a completely new discipline, that bane of all sociology students, statistical demography.
Graunt was the son of a draper who earned his living as a haberdasher; he was active in politics and became interested in demography producing the first statistical analysis of life expectancies and rates of death based on an analysis of the London Bills of Mortality, weekly announcements of the deaths in London. He published the results of his work, in which he was probably assisted by his close friend William Petty, in his Natural and Political Observations mentioned in a following index, and made upon the Bills of Mortality With reference to the Government, Religion, Trade, Growth, Ayre, diseases, and the several Changes of the said City in 1662. His book also included the first sensible and probably accurate estimate of the population of London, 384 000. As always in the history of science Graunt’s work did not appear out of thin air but built upon earlier writings on probability by Cardano, Pascal and Fermat amongst others as well as the statistical work of Richard Witt and James Howell.
Graunt’s pioneering work was developed by Petty in his Political Arithmetic, published posthumously in 1690, and Edmund Halley in his An estimation of the degrees of mortality of mankind published in the Philosophical Transactions of the Royal Society in 1693. In Holland the Cartesian mathematicians Jan De Witt and Johann Hudde both made significant contribution to the science of statistical demography in the same period.
In his private life Graunt suffered twice through the Great Fire of London. He lost all of his property and with it his wealth in the fire and having recently converted from the Puritanism of his youth to Catholicism he was accused of having laid the fire, charges of which he was finally cleared. Amongst statisticians and historians of statistics he is regarded as the ‘Columbus’ of demography and the distinguished epidemiologist Kenneth J. Rothman writing in Lancet said of Graunt, “With [Graunt’s book on the Bills of Mortality] he added more to human knowledge than most of us can reasonably aspire to in a full career.”