Every other year or so I find myself returning to Theodore Schick and Lewis Vaughn’s critical thinking text, How to Think about Weird Things, and rereading the whole darn thing through again. Schick and Vaughn’s book is a rather popular college text, and it’s in its sixth edition. My references to it will be from the 5th edition. In any case, it’s really, really good. And this time in reading it, I thought that I might generate a blog post to accompany each chapter, responding to things that leap out at me on this particular read-through.
I gave a blog response to chapter 1 here. And what, in chapter 2, did I find particularly notable?
First, a matter of emphasis. I think it’s interesting that Schick and Vaughn, as they get into the meat of their book, put at front and center, ala Thomas Kuhn, the importance of paradigms, which I would put this way:
- Be aware of the paradigm—the worldview/theoretical framework—that you are reasoning from
The example that they use is an excellent one, for it illustrates how your worldview can lead to incorrect inferences with regards to data and evidence: On hearing of a meteorite dropping to Earth, Thomas Jefferson famously declared that he would sooner believe that individuals bearing witness to such a thing were lying as to believe that rocks actually fall out of the sky. Here’s Jefferson’s exact quote (15):
I could more easily believe that two Yankee professors would lie than that stones would fall down from heaven.
Jefferson believed that he had arrived at the most parsimonious explanation for meteorite claims, and was not just wrong, but spectacularly so. The lesson (to echo Shakespeare): there may well be more things in our material heaven and Earth—and outside of them—than are dreamt of in our current philosophies—or paradigms—Horatio.
Here’s the second thing that Schick and Vaughn set at the front and center of critical thinking, and which I would put this way:
- Always keep in mind the difference between logical possibility and physical impossibility
There are things, in other words, that are logically possible but not physically possible. A cow, for example, could logically jump over the moon—there is nothing in logic that prevents this—but there are things that we have discovered about the nature of the physical world that make this impossible (for one, a cow’s hind muscles do not generate enough force to escape Earth’s gravity). This, I think, is a clever way for Schick and Vaughn to entangle good reasoning with evidence and data: it’s not enough to think clearly, you should try to produce physical evidence for your claims as well. Our confidence in a thing being true rises wherever our reasoning is sound and there is good physical evidence that accompanies our beliefs.
As an aside to this central point about logical possibility and physical impossibility, Schick and Vaughn also discuss technological possibility: a thing may be technologically possible, but may never become actual.
An illustration of how Schick and Vaughn bring their reflections on paradigms, logical possibility, and physical impossibility together is in their discussion of precognition: what are we to make of people who claim to have seen the future? Notice how Schick and Vaughn first make the very coherence of the idea dependent on logic, and the nature of the paradigms and evidence surrounding it:
[T]here are models of physical reality, consistent with all known physical laws, in which the future does exist now. Such models draw their inspiration from Hermann Minkowski’s interpretation of Einstein’s special theory of relativity.
Einstein’s theory of relativity provides a way of looking at the universe that makes it both logically and physically possible for the future to exist now. This view of the universe has come to be known as the ‘block universe’ view because it takes the universe to be a static, unchanging ‘block.’ But the universe doesn’t seem static. So what creates the illusion of change? Some believe it is created by the interaction between our consciousness and our four-dimensional selves.
Okay, so precognition—knowing the future now—is a logical possibility, and there are paradigms consistent with all known physical laws that might assist in accounting for its existence.
But is precognition real? Show me the evidence.
And here we encounter a sidebar titled “The Psychic Scorecard” (29) which briefly touches on the bleak track record of professional psychics. Precognition may be logically possible and consistent with some paradigms that do not violate physical law, but if the actual direct evidence for it is poor or ambiguous, then we should be cautious about believing that it really exists.
Schick and Vaughn are also good at drawing out additional implications surrounding claims. Belief in precognition, for example, if it is accounted for within a block universe paradigm, may logically compel you to reject the idea of human freedom:
You are free to do something only if you can refrain from doing it. . . . So if the future is determined, as precognition suggests, then only one course of action is open to you, and you are not free to do otherwise.
This, in my view, is a brilliant illustration of the notion that ideas have consequences and are interlinked. Beliefs are not a buffet. The ones that you choose to put on your plate interact with each other—and, if you choose wildly, they can challenge your very own intellectual coherence.
And so, if you insist that you have existential freedom—that you are not a ‘robot’—perhaps that also necessarily means that you are not a psychic either:
But here’s where Schick and Vaughn’s relentless critical thinking—treated as a universal acid—could lead to mischievousness, for might such insistence on intellectual coherence in all matters drive one, well, mad?
The early 20th century Catholic essayist and detective fiction writer, G.K. Chesterton, thought it might. Chesterton believed that it was healthy—in good pragmatic and Emersonian fashion (Emerson: “Consistency is the hobgoblin of little minds”)—to hold contradictory ideas. This is very like the poet’s capacious habit of looking at the world from very different vantages and metaphors without any rushing to artificially reconcile or justify them (otherwise known as negative capability). Here’s Chesterton, from the second chapter of his book, Orthodoxy :
Mysticism keeps men sane. As long as you have mystery you have health; when you destroy mystery you create morbidity. The ordinary man has always been sane because the ordinary man has always been a mystic. He has permitted the twilight. He has always had one foot in the earth and the other in fairyland. He has always left himself free to doubt his gods; but (unlike the agnostic of to-day) free also to believe in them. He has always cared more for truth than for consistency. If he saw two truths that seemed to contradict each other, he would take the two truths and the contradiction along with them. His spiritual sight is stereoscopic, like his physical sight: he sees two different pictures at once and yet sees all the better for that. Thus he has always believed that there was such a thing as fate, but such a thing as free will also. . . . It is exactly this balance of apparent contradictions that has been the whole buoyancy of the healthy man. The whole secret of mysticism is this: that man can understand everything by the help of what he does not understand.
I think that the above quote is something to ponder as a contrast to Schick and Vaughn. Chesterton is clearly dismissing the importance of maintaining intellectual coherence in discourse. This is a very serious attack on critical thinking itself. Coherence is something that Schick and Vaughn, later in their book (in chapter 4), insist is a crucial element to any reasonable person’s claim to knowledge (75):
Ordinarily, if a proposition fails to cohere with the rest of our beliefs, we are not justified in believing it.
Still, Chesterton would seem to have support from important philosophers like Isaiah Berlin and Richard Rorty, who long suggested that we should use different language tools for different problems, and that not everything in life holds together in a neat way. Maybe they’re right. Maybe ideas needn’t hold together too tightly or coherently for them to be useful to us. Maybe the way we talk about one thing is not the way we should talk about another. In applying critical thinking, is there ever a moment where common sense—or other considerations—should restrain us (lest we miss the forest for the trees)?
Whose forest? Which trees?