Ebook: An Enquiry concerning Human Understanding (Oxford World's Classics)

This volume earns the names "thin" and "compendious" at the same time. In typical Oxford fashion, it contains not merely the original text and modern notes, but a collection of further relevant appendices, including an abstract from the later "Treatise of Human Nature", an essay on the "soul" intended for the Enquiry but published separately later, posthumous dialogues concerning the subject matter, excerpts from Hume's letters which address the Enquiry, a short autobiography published in the year of Hume's death, and glossaries and multiple indices.

Hume appears to have regretted his publication at such an unripe age of the Enquiry, which at first did not sell well and brought still-dangerous accusations of atheism. Indeed, the accusation of atheism could still be lethal in contemporary Europe, and Hume always approaches the subject indirectly, including pro-forma acknowledgements of a Creator, with his more daring work published separately as anonymous or posthumous essays. Nevertheless, his early work built up a following in later years and ultimately rendered him financially independent.

The fundamental achievement of this work must be its strong philosophical case for empiricism as the basis of all knowledge of the world that is worth the name. "When we run over libraries, persuaded of these principles, what havoc must we make? If we take in our hand any volume, of divinity or school metaphysics, for instance, let us ask, 'Does it contain any abstract reasoning concerning quantity or number? No. Does it contain any experimental reasoning concerning matter of fact and existence?' No. Commit it then to the flames. For it can contain nothing but sophistry and illusion." Hume places this judgement on a footing which seems undeniable. What do we know of causation other than as a generalisation of necessary relationships gathered from experience? Nothing. What do we know of the intrinsic properties of objects that can be ascertained by pure reason without ever having observed them? Nothing.

Hume was deeply sceptical of any inference about objects not directly observed - the nature of causation and even of forces and the like could not directly be seen. I wonder how he would have dealt with today's increasingly indirect and specialised science, where a particle in an accelerator is often a mere representation on a computer display? We cannot know, but I am sure his opinion would have been worth hearing.

Hume is also worth listening to on miracles, which he rejects as never having been sufficiently testified to in all of human experience - although, mark you, he does not reject in principle their possibility. No, his point is that no testimony suffices to provide assurance of a miracle's occurrence. A miracle requires human testimony, which is fallible. It is easier to believe in the failure of testimony than the failure of the laws of nature, hence no testimony suffices to demonstrate a miracle save that the falsity of the testimony would be yet more miraculous than the event itself.

Hume's 18th-Century circumlocution makes his text a little more difficult to read than modern English-language philosophers or the ancients, but Hume is arguably the greatest philosopher of the English language. His ideas and friendship influenced Adam Smith and he is a key figure of the Scottish Enlightenment. Anyone interested in Enlightenment thinking, epistemology, humanism or atheism ought to make their self familiar with this work.