February 6, 2021


Tree of Knowledge (Rick Lewis, February 2021, Philosophy Now)

Some people say that the central strand in the history of philosophy is the search for truth. Conversely a tendency in philosophy for thousands of years has been scepticism - philosophical doubt about our ability to know particular things, such as the existence of the external world, or of other minds, or of moral certainty, or of the existence of God. Radical scepticism is doubting our ability to know anything at all. Descartes started with that position. Surrounded by sceptics on all sides, he wanted to find certainty. So he went one better than them by doubting everything. In a famous thought experiment he imagines an evil demon "of the utmost power and cunning" deliberately setting out to deceive him about everything. And then he thought, is there anything I could still know in such a situation? And he answered himself - yes. Even if he was being deceived about everything, then his thoughts while erroneous would still be thoughts. So he knew one thing: "I think" And from that he knew a second: "Therefore I exist."

David Hume at 300 (Howard Darmstadter, February 2021, Philosophy Now)

To see the emphasis Hume placed on our thought processes, consider a familiar philosophical problem. Seeing an external object - a tree, for example - involves a process that begins with the tree and flows, via reflected light, to our eyes, and then up our optic nerve to our brain, to produce a mental image of the tree, which is our experience of the tree. The tree is at one end of this chain of events, our mental image of the tree at the other. So how can we be sure that our mental image of the tree is like the tree itself? Descartes had a classic formulation of this problem: Could there be an evil demon who systematically gives us experiences (mental images) that are different from their causes? A modern version of this problem is, How do you know that you're not just a brain in a vat, fed electrical impulses by a mad scientist, so that while you think you have a body and participate in a real world of people and objects, you are in reality only a player in a kind of cosmic video game? (You've seen the movie.)

But Hume does not attempt to answer Descartes' problem. Hume's vantage-point is always that of a psychologist attempting to explain human behavior. The psychologist accepts that he and his subjects inhabit a common world of people and material objects. It is from within this common world that the psychologist attempts to discover the laws of thought. We can speculate as to whether this common world really (ie observer-independently) exists as we imagine it, but for Hume such speculations are idle. People always assume that such a world exists, and the psychological imperative to make this assumption settles the question for Hume. As he says in the Enquiry Concerning Human Understanding, skeptical principles "may flourish and triumph in the schools, where it is indeed difficult, if not impossible, to refute them. But as soon as they leave the shade, and by the presence of the real objects, which actuate our passions and sentiments, are put in opposition to the more powerful principles of our nature, they vanish like smoke, and leave the most determined skeptic in the same condition as other mortals" (from Part II of Section XII).

The Humanist

Just as our reasonings concerning matters of fact rest on a principle of association of ideas, so there can be no 'ultimate' justification for our moral beliefs, beyond psychological laws. This is summarised in Hume's infamous law that 'you can't get an ought from an is' [See Hume on Is and Ought in this issue - Ed].

Hume's attempt to base morality on psychological principles begins with a conventional premise: humans are motivated by pains and pleasures. But Hume insists that humans are innately social: we take pleasure in the pleasure of others, and feel pain at others' pain. This 'principle of humanity' is the foundation of Hume's ethical theory. It is his gravitational principle. It's our motivation for what we might call our 'moral behavior'. Hume supports it with numerous examples drawn from everyday life, but disdains any attempt to explain it.

Hume never doubts that all people are united in possessing the same psychology, in particular, the principle of humanity. Our fellow-feeling can be extended to anyone with whom we have contact: "An Englishman in Italy is a friend, a European in China, and perhaps a man would be beloved as such were we to meet him in the moon." Of course, the empathy shown in the principle of humanity does not extend to humankind generally, but only to people with whom we have contact: most strongly to family members and close friends, less to acquaintances, still less to those with whom contact is intermittent, and hardly at all to strangers. Hume's principle thus fails to explain how people can live at peace in complex societies where they must interact with and depend upon relative strangers. Instead, since large societies are necessary to maximize human pleasure - a basic human motivation to Hume - in this case people use their reasoning ability to invent systems of legal rules and institutions:

"Two neighbors may agree to drain a meadow, which they possess in common, because 'tis easy for them to know each others mind; and each must perceive that the immediate consequence of his failing in his part is the abandoning of the whole project. But 'tis very difficult, and indeed impossible, that a thousand persons should agree in any such action... Political society easily remedies ... these inconveniences. Thus bridges are built; harbors opened; ramparts raised; canals formed; fleets equipped; and armies disciplined everywhere by the care of government, which, though composed of men subject to all human infirmities, becomes, by one of the finest and most subtle inventions imaginable, a composition which is, in some measure, exempted from all these infirmities."

Treatise of Human Nature, Book III, Part II, section vii.

Yet while reason finds the means for individuals to achieve their ends, those ends are not set by reason, but by irresistible mental tendencies which Hume calls 'sentiments' or 'passions'. "Reason is, and ought only to be, the slave of the passions, and can never pretend to any other office than to serve and obey them" Hume claimed.

Is Skepticism Ridiculous? (Michael Philips, February 2021, Philosophy Now)

David Hume (1711-76), perhaps the greatest skeptic of them all, struggled valiantly with this conflict. According to Hume, we face a difficult dilemma. On the one hand, we must respect philosophical reasoning (or, as he calls it, "refin'd reflection"). It is our only defense against ignorance, superstition, and other beliefs governing daily life which, one and all, originate in 'illusions of the imagination'. On the other hand, we can't run our lives on the conclusions of refin'd reflection since

"...the understanding, when it acts alone, and according to its most general principles, entirely subverts itself, and leaves not the lowest degree of evidence in any proposition, either in philosophy or common life." [This and the following Hume quotes are from A Treatise of Human Nature, Book I, Part IV, section VII].

Midway through his discussion, Hume asserts that there is no rational solution to this problem, but that we don't need one. Although reason makes no headway here, 'nature' seems to solves the problem in favor of 'common life.' One can only entertain skeptical conclusions for so long before

"...[nature] cures me of this philosophical melancholy and delirium, either by relaxing this bent of mind, or by some avocation and lively impression of my senses, which obliterates all these chimeras. I dine, I play a game of back-gammon, and I am merry with my friends; and when after three or four hours' amusement, I wou'd return to these speculations, they appear so cold, and strain'd, and ridiculous, that I cannot find it in my heart to enter into them any farther."

At such times Hume finds himself "absolutely and necessarily determin'd to live, and talk, and act like other people in the common affairs of life." Thus reduced to this "indolent belief in the general maxims of the world" he is ready to throw "all my books and papers into the fire, and resolve never more to renounce the pleasures of life for the sake of reasoning and philosophy."

Reason is not rational--so what?

Posted by at February 6, 2021 11:00 AM