David Hume Asks Why
September 23, 2024
I tortured myself by reading The Cambridge Companion to Hume. Or trying to. Hoping to gain some fresh insight.
David Hume (1711–76) was a Scottish philosopher. Among the greatest ever. He was relentlessly rationalist, always seeking solid, evidence-based explanations, often for matters we take for granted, but which might not withstand piercing examination. Of course he was totally down on religion.
This 1993 book is a collection of essays by varied authors dilating upon Hume’s thought. The dense prose was very hard to slog through. Maybe not like the worst of social-science academese, but often close. I craved some plain English. And concrete illustrations of what the writers were talking about.* The first one found on page 77 felt jarring.
In Hume’s day, philosophical debate swirled around the basis for morality. Rejecting any supernatural source, Hume saw morality as being embedded in human nature; while others argued that people act solely from self-interest and all supposed moral precepts are baseless piffle. In the latter camp was Hobbes, yet his social contract theory actually points to reconciling both. We enter society, relinquishing freedom to treat others unjustly, in exchange for its protecting us against their treating us unjustly. That deal is in one’s self-interest. Enlightened self-interest, grounded in reason.
Further, such reciprocity was bred into us by evolution, because it did serve everyone in a group. Hence we feel good when doing right, and bad otherwise. And it’s self-interested to do things producing good feelings for oneself. This underlies altruism. Even soldiers sacrificing their lives are not totally selfless. They avoid feeling bad.**
Meantime, I’d picked up the book because I relate to Hume’s grappling with that great mystery of the self. Can’t say he solved it. But he was a pioneer in trying to illuminate just how perplexing a problem it is.
An aspect of this is the issue of causation. A concept integral to how one’s self positions itself in the world. It might seem a pretty simple, straightforward idea. But not in Hume’s inquisitive hands. What it truly means to say one thing causes another turns out to be not so simple after all. Indeed, the concepts of the one thing and the other are themselves sticky wickets.
Further still, a lot of what we think of as causation entails the laws governing the cosmos. Like things falling because of gravity. Teasing out such laws of existence was crucial to someone like Hume, striving to understand the world at the deepest level, of empirical materialism.
Here again Hume was always seeking for the ultimate “why.” Recursively, behind every answer there always seems to be another question: why is that so?
Yes, things fall because of gravity. But why is there gravity? Newton brilliantly figured out how gravity works, mathematically, but was clueless about how, physically, it works. This was the problem Einstein characterized as “spooky action at a distance.” Hitting a ball with a bat, it intuitively makes sense to us that the ball flies off. The bat transmits force to it (another of Newton’s laws). But what if bat and ball never touch? Swing all you like and the ball won’t budge. Yet gravity requires no physical contact to make something move.
Einstein solved this puzzle with gravity acting not on objects directly but instead by warping the space around them. Makes sense, kind of, and we think it’s true. But Hume might have asked: how, exactly, does gravity warp space? Isn’t that still action at a distance?
Hume predated Einstein, of course, but not Newton. Who discovered that the force of gravity diminishes with the square of the distance between objects. That’s a law of nature. But why, Hume asked, is that the law? Why not proportional to the distance? Or to its cube? Or any other rule? No god set up the Universe decreeing such laws. What does make them what they are?
And — for that matter — why are there laws? Why do they explain causation?
Is it turtles all the way down?
I recall when my two-year-old met every answer with another “why?” Was she channeling Hume?
* An essay on Hume’s political thought repeatedly refers to Whigs versus Tories, with no clarity about them. So I went to the footnotes and happily found a lengthy one that begins, “Hume explains the labels ‘Whig’ and ‘Tory’ . . . ” However, the footnote studiously avoids that explanation.
** For a deeper discussion, See F.S. Robinson, The Case for Rational Optimism, 2009.