Stephen Hicks, Ph.D.

David Hume’s current influence

David Hume tops this PhilPapers survey of most influential and admired philosophers (scroll down to bottom of the page to “Non-living philosophers most identified with”).

Aristotle comes in second (yeah!) and Kant third (boo!). I’ve been thinking much about Nietzsche and Heidegger recently: eleventh and eighteenth, respectively. Overall, the list is still dominated by thinkers in the Analytic pantheon.

I have mixed feelings about Hume. He is often excellent as a critic of the traditional arguments for religion, and he is often shrewd in applied ethics and political economy. For example, I like very much this early statement of the benefits of money to facilitating free trade and comparative advantage:

“There seems to be a happy concurrence of causes in human affairs, which checks the growth of trade and riches, and hinders them from being confined entirely to one people; as might naturally at first be dreaded from the advantages of an established commerce. Where one nation has gotten the start of another in trade, it is very difficult for the latter to regain the ground it has lost; because of the superior industry and skill of the former, and the greater stocks, of which its merchants are possessed, and which enable them to trade on so much smaller profits. But these advantages are compensated, in some measure, by the low price of labour in every nation which has not an extensive commerce, and does not much abound in gold and silver. Manufactures, therefore gradually shift their places, leaving those countries and provinces which they have already enriched, and flying to others, whither they are allured by the cheapness of provisions and labour; till they have enriched these also, and are again banished by the same causes. And, in general, we may observe, that the dearness of every thing, from plenty of money, is a disadvantage, which attends an established commerce, and sets bounds to it in every country, by enabling the poorer states to undersell the richer in all foreign markets” (“Of Money” 1752).

Hume’s important weaknesses are in epistemology. He is an empiricist, which is great, but his empiricism is extremely atomistic, mechanical, and reductionistic. That approach leads to his skeptical conclusions about the perception of objects, about abstraction and concept-formation, about inductive generalization, and, metaphysically, about the reality of causality and the persistence of identity across space and time.

A sideways connection: It turns out that John Hunter, the surgeon and anatomist about whom I posted The Knife Man and Anatomy and philosophy, examined David Hume when Hume was in his final decline. In 1775 Hume began to suffer terrible abdominal pains, and, unfortunately, was attended “by the most eminent physicians of the day.” As biographer Wendy Moore puts it:

“None of them could offer a satisfactory explanation or effective remedy for Hume’s obvious decline. Though they were very happy to posit elaborate theories and propose assorted therapies, nobody was prepared to examine the patient in order to determine what might be causing his suffering” (italics added). The empiricist philosopher was surrounded by un-empiricist physicians.

John Hunter was called in by happenstance. Hunter and Hume were indirectly related through marriage, and in June of 1776 both men were in Bath. By then, Hume’s condition was very bad and Hunter was invited to examine him. Writes Moore: “Hunter laid his hands on the suffering man’s abdomen and could plainly feel a tumor, which he suspected was cancerous, in the liver” (p. 183). Internal abdominal surgery was not a realistic option, and the philosopher died two months later, back home again in Scotland.

Hume was philosophical in the best sense of the word when he learned, finally, about his condition. Writing frankly and forthrightly to his brother: “This Fact, not drawn by reasoning, but obvious to the Senses, and perceived by the greatest anatomist in Europe, must be admitted as unquestionable, and will alone account for my Situation.”

Anatomy and philosophy

Following up on The Knife Man and John Hunter, the great 18th-century anatomist and surgeon. In Hunter’s era surgery was brutal, in large part due to surgeons’ ignorance of anatomy, and in that earlier post I wondered why there was still such ignorance given that the 1700s were two centuries after Andreas Vesalius and a century after Francis Bacon.

Here’s my hypothesis: Philosophy has a lot to do with it.

Suppose you’re an early physician — your patients suffer and die, and you don’t know why. One option is not to think much of it: bad stuff happens, people die, accept it. It takes an active mind — curiosity, interest, follow through — for science to get going. Why do people die?

Even if you do decide to think about it, there are further obstacles.

One is the historically common belief that the gods cause things to happen. That metaphysical belief will stop you from looking for natural, anatomical causes.

If you reject religious cause-and-effect and suspect that the cause might be anatomical, there are aesthetic obstacles — think of the sights you will see, the textures you will feel, and (probably the worst) the odors you will smell.

There are moral obstacles: anatomy seems to disrespect the dead or to disrespect the living person the corpse once was. Moral obstacles might also be based on particular religious metaphysical beliefs, such as the resurrection of the body and so wanting to preserve the body intact for that eventuality.

So philosophy — metaphysics, morality, and aesthetics — can stop the impulse that leads to anatomy. And based on some or all of the above, there will be legal obstacles.

To those obstacles, all of which were operative in early modern Europe, let me add the epistemological barriers.

One was the reverence for tradition. Religion emphasized tradition, and the Renaissance respect for the ancients’ accomplishments often meant merely substituting a Greek or Roman authority for a Judeo-Christian one. For the early modern understanding of the inner workings of the human body, Galen’s humor theory was the mostly-unquestioned authority.

To the extent that early scientists were willing to think independently of traditional authorities, many simply speculated and spun theoretical just-so stories. An example here is Albrecht von Haller, a Swiss contemporary of John Hunter, who, based on no observational evidence, argued that every embryo was from day one already a perfect miniature of the mature organism and that embryonic development was merely a matter of increasing size.

And to the extent that anatomy was done, it was most often performed as a demonstration of traditional or speculative theories. Students would crowd around the anatomist while the professor read from the authoritative text telling the students what they were seeing. This usually meant that top-down confirmation bias simply reinforced the traditions and speculations.

So early anatomy was hobbled by three faulty epistemologies:

Tradition — the unthinking acceptance of others’ thinking.
Speculation — thinking independent of observation.
The demonstration method — observation only as the hand-maiden to thinking.

The primacy of observation: that epistemological principle had to be articulated and institutionalized. That is what Francis Bacon did for philosophy in the 1600s and what John Hunter did for anatomy in the 1700s.

Empiricism made anatomy possible. Anatomy made internal surgery possible. Surgery made dramatic live-saving and life-improvements possible. Conclusion: Philosophy is very practical.

Related:

My posts on Aristotle on the aesthetics of the “humbler animals” and Francis Bacon as the founder of modern philosophy.

Wendy Moore’s The Knife Man: Blood, Body Snatching, and the Birth of Modern Surgery [Amazon's site].

Sherwin Nuland’s Doctors: The Biography of Medicine [Amazon's site]. I love the chapter on Vesalius.

The Knife Man

I am reading Wendy Moore’s The Knife Man: Blood, Body Snatching, and the Birth of Modern Surgery. A fascinating book, but not for the squeamish.

The key figure is John Hunter, an 18th-century anatomist and revolutionary surgeon of volatile temperament, with a hunger for knowledge that drove him to rob thousands of graves, record the tastes of corpses’ bodily fluids (”gastric juice,” apparently, “is a little saltish or brackish to the taste”), deliberately infect himself with syphilis, and … well, you should read the book.

Surgery in the 1700s was brutal, in large part due to surgeons’ appalling ignorance of anatomy. Moore puts it this way:

“Although medical students usually learned some rudimentary anatomy, this was considered a useful but not vital adjunct to on-the-job experience. And when patients died on the operating table as a result of ignorance and blundering, as they frequently did, few, if any, lessons were learned from the outcome.”

Antiseptic and anesthesia were not discovered until the 1800s, so the brutality and low success rates of surgery in the 1700s make some sense. But the ignorance of anatomy is odd — after all, the 1700s were two centuries after Andreas Vesalius and one century after Francis Bacon. How slowly things change sometimes.

The revolution in anatomical knowledge pioneered by Vesalius and the epistemological revolution pioneered by Bacon — with its emphasis on observation and experiment — had not yet reached English medicine, or only barely so. As Moore puts it, “treatment regimes still owed their basic principles largely to the theories of the ancient Greeks.” The reverence for tradition and authority was so strong that it took a pugnacious, thick-skinned man like Hunter to be willing to crack heads, literally and metaphorically, with his colleagues to get them to consider new methods.

I’m just starting Moore’s book. Exams are over for me at the end of next week, so I will follow up with more then.

For now, there’s more on John Hunter at the Endocrine Today site.

Follow up: My post on Anatomy and Philosophy.