David Hume (1711-1776) Scottish man of letters and philosopher, who brought his common-sense skepticism to the subject of metaphysics. Hume concluded that it was impossible to establish certain knowledge through reason. Men had only their experience to rely on, and there was no overall scheme of things. Hume's ideas made little impact in his own lifetime; he was rejected for the professorship of moral philosophy in his native Edinburgh. His largest work, the Treatise of Human Nature, which he completed before he was 27. His subsequents philosophical works were similarly overlooked, while his historical writings, although noticed, gained little respect. His work, however, greatly influenced later thinkers, notably Immanuel Kant and Jeremy Bentham. Hume's contemporaries valued him more for his personal qualities. Adam Smith, an economist. said of him: 'I have always considered him, both in his lifetime and in his death, as approaching as nearly to the idea of a perfectly wise and virtuous man as perhaps the nature of human frailty will admit'.