is an obvious and, one must own, a not altogether unsuccessful attempt "to write wittily about these matters[1]."
The third group of arguments—those based upon the probabilities of the case—should be considered as corroborative, rather than as of independent weight. In advancing them the partisans of each writer must seek to strengthen a case already built up by direct testimony and internal evidence rather than to establish their contentions ab initio[2]. In general, the probabilities strongly favour Graunt. In the first place, he was a citizen and a native of London. He thus had opportunity to collect the bills and incentive to study them; and the author's account of the way in which he came to make the study tallies in every particular with the known facts of Graunt's life. Petty, on the other hand, was of provincial birth, and had been a resident of London but a short time when the "Observations" were published. In the second place, the "Observations" are not the product of a few leisure hours, or even of a few hurried weeks. Their laborious compilation demanded time—how much, those will best appreciate who have attempted similar tasks. Graunt may well have had the necessary leisure, whereas Petty, in defending his Irish survey, in writing for the Royal Society, and in working for political self-advancement at the Restoration, must have been otherwise well occupied during the years 1660 and 1661[3]. In the third place, the assumption that a man of Graunt's standing in the city would consent to be a screen for Petty's book, has never been put upon a sound basis, or indeed upon any basis at all. Finally it may be noted that the "Observations" contained nothing offensive[4]; they were not only novel, but popular, and it was by no means Petty's nature to refuse credit for a good thing which he had done[5]. Nevertheless the "Observations" had been out almost fifteen years, had passed through four editions, and had received unusual honours at the hands of the Royal Society, and apparently of the king also, before there was a whisper of Petty's authorship.
Opposed to these probabilities in favour of Graunt stand two analogous arguments for Petty. One argument Dr Bevan advances: