David Hartley on human nature

In each of the subjects under discussion there were intense efforts to determine chemically the active constituent of the medicine. It was success in this field, with the isolation of the alkaloidal constituents of opium, cinchona bark and nux vomica in the first decades of the nineteenth century, that supported the view that scientific pharmacology had its origins at that time. In this interesting monograph the author argues that experimental pharmacology and therapeutic innovation were already prominent features in eighteenth-century practice. Though arguably amongst the half-dozen leading intellectuals of eighteenth-century England and a man of immense influence in psychology and pedagogics, David Hartley has been oddly neglected: he rarely makes more than a passing appearance in histories of the Enlightenment and there is no recent biography. Amends have partly been made in Richard C Allen's study-a work which combines deep erudition with a very congenial manner and an engaging prose style (it is, all too predictably, the work of someone who is not currently an academic). It should be made clear from the outset that, though investigating particular episodes of Hartley's life in some detail, for instance his suffering from the stone and quest for a lithontriptic-matters now dealt with more satisfactorily in Andreas-Holger Maehle's Drugs on trial: experimental pharmacology and therapeutic innovation in the eighteenth century (Amsterdam, Rodopi, 1999)-this is not a conventional biography. In particular, it is frustrating that Allen has so little to say about Hartley's crucial Cambridge years and contacts. The focus of Allen's attention is Hartley's Observations on man, his frame, his duty, and his expectations, published in two volumes in 1749. That is a work whose significance has often been touted by those, from Joseph Priestley onwards, who have butchered or twisted it in various ways for their own ends. In his re-edition of the Observations, Priestley for his part, while at least valuing Hartley's materialism, completely expunged his theory of nervous vibrations; while later Utilitarians, though setting him up as one of their forefathers, pretended that Hartley had written a secular theory and thereby entirely ignored the second volume. Allen aims to restore the Observations to its original historical context and to recover Hartley's intentions. In that endeavour he is largely successful. He is equally well-read in modem scholarship on, and expert in the byways of, early-Georgian philosophy of mind and neurological controversy (were the nerves hollow or not?), and so proves very …