David Hume, the 18th century Scottish philosopher (1711-1776), is a favorite of modern day scientists and scientifically-minded philosophers.
Somehow I'd reached the age of 64 without reading all of his "Concerning Human Understanding," even though my mother bought the Great Books of the Western World series when I was about nine -- and I inherited the collection when she died.
I'm getting to know Hume now. And am liking him a lot. Sure, he writes in a style that seems stilted. But his ideas about experience, cause and effect, religious belief, and such are wonderfully up to date.
I'm most of the way through "Concerning Human Understanding." Today I read a section where Hume talks about how much we can infer an intelligent designer, a.k.a. God, from what can be observed in nature.
Here he writes in the fictional voice of Epicurus, who is addressing Athenians concerning about Epicurus' denial of a divine existence.
You then, who are my accusers, have acknowledged that the chief or sole argument for a divine existence (which I never questioned) is derived from the order of nature; where there appear such marks of intelligence and design, that you think it extravagant to assign for its cause, either chance, or the blind and unguided force of matter. You allow, that this is an argument drawn from effects to causes.
Hume is big on cause and effect. He points out that a single instance of something leaves us mystified. It's like a baby who sees his mother disappear when she puts a blanket over her head, then reappears when the blanket is removed.
Repeated experience of a phenomenon creates what Hume calls "habit." Nature comes to reveal her tricks. Eventually we expect that when dropped, a ball falls to the ground. When a billiard ball rolls on a table and hits another ball, the other ball is impelled to move also.
Cause and effect is what we know of the world, basically.
Even after one instance or experiment where we have observed a particular event to follow upon another, we are not entitled to form a general rule, or foretell what will happen in like cases; it being justly esteemed an unpardonable temerity to judge of the whole course of nature from one single experiment, however accurate or certain.
But when one particular species of event has always, in all instances, been conjoined with another, we make no longer any scruple of foretelling one upon the appearance of the other, and of employing that reasoning, which can alone assure us any matter of fact or existence.
We then call the one object, Cause; the other, Effect. We suppose that there is some connexion between them; some power in the one, by which it infallibly produces the other, and operates with the greatest certainty and strongest necessity.
This is one reason Hume is so skeptical about miracles. They are one-off "experiments."
It isn't possible to examine whether natural causes explain supposedly supernatural events. Of course, if it can be shown that This always results in That, we now are in the realm of science, not religion -- even if the This and That are spookily unfamiliar. (Quantum physics is a good example.)
In what I read today, Hume cautions against reading more into a hypothesized cause than is evident in the effect.
When we infer any particular cause from an effect, we must proportion the one to the other, and can never be allowed to ascribe to the cause any qualities, but what are exactly sufficient to produce the effect. A body of ten ounces raised in any scale may serve as a proof, that the counterbalancing weight exceeds ten ounces; but can never afford a reason that it exceeds a hundred.
If the cause, assigned for any effect, be not sufficient to produce it, we must either reject that cause, or add to it such qualities as will give it a just proportion to the effect.
But if we ascribe to it farther qualities, or affirm it capable of producing other effects, we can only indulge the license of conjecture, and arbitrarily suppose the existence of qualities and energies, without reason or authority.
Philosophical language, to be sure. Yet a devastating putdown to religious belief.
What are the effects evident in the world which lead adherents of any religion to believe in a divine, supernatural, godly, or heavenly cause? Can those effects be explained without recourse to the excessively imagined Cause that can't be experientially related to them?
For example, a holy book, the Bible, contains a story that long ago a man, Jesus, died on the cross and was resurrected in a bodily form. There is no demonstrable evidence of the one-time event. It has never been observed again. There is no reasonable link betweeen the purported cause of a godly nature and the supposed effect, life after death for Jesus.
Yet a billion plus people in the world found their Christian faith on some exceedingly shaky cause and effect assumptions. These aren't based on repeated experience, which is how people learn in their everyday lives, but on imaginations/concepts produced in their own minds.
I like these parts of Hume's Section XI.
You find certain phenomena in nature. You seek a cause or author. You imagine that you have found him. You afterwards become so enamoured of this offspring of your brain, that you imagine it impossible, but he must produce something greater and more perfect than the present scene of things, which is so full of ill and disorder.
You forget, that this superlative intelligence and benevolence are entirely imaginary, or at least, without any foundation in reason; and that you have no ground to ascribe to him any qualities, but what you see he has actually exerted and displayed in his productions.
Let your gods, therefore, O philosophers, be suited to the present appearances of nature: and presume not to alter these appearances by arbitrary suppositions, in order to suit them to the attributes, which you so fondly ascribe to your deities.
...But what must a philosopher think of those vain reasoners, who, instead of regarding the present scene of things as the sole object of their contemplation, so far reverse the whole course of nature, as to render this life merely a passage to something farther; a porch, which leads to a greater, and vastly different, building; a prologue, which serves only to introduce the piece, and give it more grace and propriety?
Whence, do you think, can such philosophers derive their idea of the gods? From their own conceit and imagination surely. For if they derived it from the present phenomena, it would never point to anything farther, but must be exactly suited to them.
That the divinity may possibly be endowed with attributes, which we have never seen exerted; may be governed by principles of action, which we cannot discover to be satisfied; all this will freely be allowed. But all this is mere possibility and hypothesis.