Philosophers pride themselves on thinking clearly, seeing what follows from what, uncovering sophisms, spotting fallacies, and generally monitoring our reasoning. Many have spent years honing their abilities, often using them on arcane subjects. But these skills are not the exclusive property of refined sages, accessible only with a secret handshake and insider training, much as some philosophers would like them to be. Instead, some of these skills can be captured through generalizable, universal techniques for the right mindset, regardless of the topic. Many of these are easy to teach and learn. As such, they can also be used by non-philosophers. At a time when we are being bombarded with flimsy claims and false conclusions more than ever, clear thinking offers a much-needed protection that we should all strive for.
Philosophers attach great importance to certain tools for regimenting our thinking, especially logic and probability theory. However, we have a far richer toolbox at our disposal. Over the years I have watched philosophers employ various argumentative grips or strategies that can be summed up in rules of thumb that make their work easier. These could be namedphilosophical heuristics.That shouldn't come as a surprise: pretty much every complex activity has its heuristics that experts teach and beginners learn — photography, calligraphy, scuba diving, driving, soccer, foosball, judo, cluedo, curling, slingshots, rock climbing, rhyming, and so on. Such heuristics are particularly well documented for chess: "castle early and often", "check every check" and what do you have?
There are also common heuristics for intellectual pursuits like math and creative writing. Here's a good one for math: If you're stuck on a problem, modify it slightly to make it easier and solve this one. A good heuristic for creative writing is to juxtapose familiar words and phrases in unfamiliar ways. One could use the "cut-up technique" popularized by William S. Burroughs and David Bowie, in which written text is cut up and rearranged to create new text.
Still, one might assume that philosophy is particularly unsuited to such heuristics. The word "philosopher" comes from ancient Greekphilosophers, meaning "lover of wisdom." And wisdom, a skeptic might insist, is not so easily attained. Philosophy strives for deep, profound insights, but heuristics might be viewed as superficial in nature. I'm not suggesting that philosophical heuristics offer shortcuts to depth any more than chess heuristics offer shortcuts to becoming a grandmaster. That is, Grand MasterAgainusually castle early and often, checking every move, consciously or unconsciously; A chess textbook that ignores this heuristic would be remiss. Good philosophers tooAgainI use the heuristics I identify, consciously or unconsciously, often in the service of deeper insights. In fact, philosophy textbooks have carelessly ignored these heuristics.
If we consider logic and probability theory as general-purpose tools for testing the consistency and coherence of our claims at a high level of abstraction, then the philosophical heuristics together form more of a Swiss army knife. Some of these heuristics have a wide application, like an LED light. Others have a narrower application but are perfect for the occasions when they are applied, like a corkscrew. There is something of a trade-off between how often a particular heuristic is applied and the specificity of its advice. Too general, and the heuristic doesn't provide an applicable strategy—e.g., "Say something insightful!" Too specific, and it can never be used in another context—e.g., "the answer toPascals Wette(that you should believe in god because that's the best bet) is that it leaves open which god you should believe in. The best heuristics find "sweet spots" in this compromise.
I work in the Western "analytical" tradition of philosophy. Much of analytic philosophy consists of arguing for positions. So some terminology is needed here. For our purposeStreitis a set of premises followed by a conclusion, where the premises are designed to support the conclusion. AvalidArgument is one where the support is as strong as possible: the truth of the premisesThe guaranteethe truth of the conclusion. AKlangArgument is one that is valid and whose premises are true (and therefore its conclusion is also true). AunhealthyArgument is either invalid or has at least one false premise.
LLet's start with a heuristic that is easy to use but very fruitful. The word "the" is the most common word in English. An idiom of the form "...the X..." - what philosophers call aclear description –usually comes with an assumption that there isexactly oneX. We could perhaps challenge this assumption in two ways: Maybe there ismore than oneX; maybe there isNOxs So the heuristic here is to see the word “the” in neon lights, so to speak — by italicizing, underlining, or otherwise mentally emphasizing it — and attempting every challenge.
Here is an example, not philosophical and certainly not profound, but nonetheless of considerable interest. In his inaugural address, Donald Trump said, "January 20, 2017 will be remembered as the day the people once again became the rulers of this nation." Here, "the" occurs three times; Let's focus on the first one (the other two have plural nouns - "people", "rulers", but even they have a uniqueness requirement - a unique group of people and rulers). "The day" assumes that there is exactly one such day. Some advocates for the power of democracy will insist that there are many such days - namely, every day the people vote. Some skeptics of the power of democracy will deny that such a day ever exists, and that includes January 20, 2017. In any case, unequivocal description faces a challenge.
Let's turn to a more philosophical example: we often talk about "doing the right thing". Sometimes there is just such an action. However, there can be different conceptions of "right" - for example, what is rational and what is moral. And even if you focus on one of those senses, there may be more than one candidate for right: multiple actions that are equally good. Or there is no such candidate. Think of moral dilemmas like the unspeakable depicted in William Styron's novelSophie's choice(1979) or Jean-Paul Sartre's of a student torn between avenging his brother's death in World War II and caring for his mother.
Accordingly, and more generally, when evaluating a claim, you mentally highlight iteverykeyword and iterate through itscontrast class, the set of relevant alternatives. Emphasizing the term and intoning the words "...as opposed to..." is helpful to emphasize this class. For example, one hears claims that "the human visual system is bad." Well, let's see: 'thehumanVisual system is bad'. man, as opposed to what? An eagle's visual system? Yes, the human visual system compares poorly. But what about a bear's visual system? A bat? Now that of man doesn't seem so bad. Let's continue: “manvisualsystem is bad". Our visual system as opposed to what? Our olfactory system? Certainly not - we are better seers than smellers. our hearing? That doesn't sound right either.
A racial stereotype can be "confirmed" all too easily by dealing solely with examples, not counterexamples, of it
Philosophers use contrastive stress to reveal the logical form of different concepts. For example, causality appears to be a two-digit relationship: smoking a pack of cigarettes a day causes lung cancer — so far, so good. But consider: smokingApack of cigarettes per day, as opposed tothreeorfour, causes lung cancer? That doesn't sound good. If anything, compared to these alternatives, smoking (only)likepack a day seems to helpimpedelung cancer. It seems socausationis at least a three-digit relation: C causes Erelative to C'. SimilarArgumentationsuggests that it even has four digits: Crather than C'causes Erather than E'.
The contrastive stress heuristic also helps detect false dichotomies, a popular strategy among philosophers. It is also a good corrective for certain cognitive biases that we are prone to:
confirmation bias, the tendency to seek and recall evidence that supports, but does not refute, one's beliefs and hypotheses; And
congruence bias, the tendency to accept a belief or hypothesis without adequately testing alternative hypotheses.
In fact, one of the most common mistakes is simply an oversightholdopposite cases. For example, a racial stereotype can be all too easily "confirmed" in the mind by focusing solely on instances of it, as opposed to counter-instances.
NNow we turn to a heuristic that is useful in several areas. Start with a potentially difficult problem: someone is making a claim intended to cover a variety of cases, and you want to see if there are any counterexamples. You may be faced with a huge search space. Where to look first Here's a simpler subproblem: checkextremelyCases to see if there are any counterexamples lurking there - the first case, or the last, or the biggest, or the smallest, or the stinkiest, or some similar superlative (always note the unambiguous descriptions!) Does the claim still hold there? This should drastically reduce your search space, as it now only affects the "corners" or "edges" of the original space.
For example, some philosophers like to make grandiose claims, such as, "Every event has a cause." Well, is that true? At first you might be blown away by its grandeur - there are many events out there! But start thinking aboutextremelyEvent - the first event, the Big Bang. There was no previous event that caused it, it didn't cause itself, and it wasn't retroactively caused by a later event, so we have our counterexample. While that assumes there was exactly one Big Bang, as far as I know that's a respectable assumption. Or consider the extreme event that isthe entire history of the universe. There are many cases of causalitywithinthis whole story, but probablyEswas not caused by anything. Each suspected cause is only part of the whole story.
Well, maybe it had a cause - namely God? keep that thought; we'll come back to that soon.
Suppose a politician tells you, "You should not follow the advice of a politician." What should you do with that advice?FollowIt? That doesn't follow advice as it was just the opposite.Do not followIt? That was the advice, so you would follow it. Self-referential paradoxes have occupied philosophers since the ancient Greeks. Georg Cantor, Bertrand Russell, and Kurt Gödel shook mathematics to its foundations by exploiting self-reference in different ways. We could set our goals lower, but still use self-reference fruitfully.
For example, philosophers debate all the timerealismon various topics - ethics, aesthetics, mathematical entities, the meaning of our words, the unobservable entities postulated by science, and even ordinary macroscopic objects. A popular definition is that realism with respect to Xs is the thesis that Xs exist independently of observers (e.g. realism with respect to electrons is the thesis that electrons exist independently of observers). But wait - what about the realism?observer? Observers do not exist independently of observers. How about: "Xs exist independently of the mind"? That doesn't work either – what about realism?Thoughts? Mind does not exist independently of mind. So the self-referential heuristic here is to give an assertion a taste of its own medicine.
Somewhat related is the ancient philosopher's technique of showing that a view (or argument) opposes oneinfinite regression– its truth (or validity) depends on the truth of a statement, the truth of which in turn depends on the truth of someOthersStatement whose truth depends on... The sequence of dependencies has no end.
Think again of the claim that every event has a cause. Focus on one event. According to the claim, it has a cause that had a cause that had a cause that...,to infinity. This is at least puzzling and maybe even worse. Another classic example is the justification recourse. To have legitimate belief in one thing, one must have legitimate belief in something else; but that requires a legitimate belief in somethinganders; and this chain of justification never ends. (There are different answers - for example that the chaintutend in a basic belief.)
Infinite regress isn't necessarily absurd—some regresses are described as 'virtuous' rather than 'malicious'. But some positions lead to the absurd: to contradiction. These positions must themselves be contradictory and therefore wrong. Here's another good heuristic in math: If you're not sure how to prove a claim, perhaps because it seems so obvious, try itReduction ad absurdumArgumentation. Suppose the claim is false and show that this leads to a contradiction. This provides aproveof the claim for which the claim is conclusively substantiated by this justification.
Philosophers often employReduction ad absurdumreasoning too. They also use a related but less conclusive technique to show that an argument doesn't hold water: "proves too much". (“Proves” is meant ironically.) Start with some argumentsAthat you think is unhealthy but you can't quite pinpoint what's wrong with it - it's a tough problem. parody it with another argument,P, which has the same structure asA, but whose conclusion is obviously wrong; thereforePis obviously unhealthy. Then argue thatAresemblesPin important respects it must also be unhealthy. This is not a proof but an example of reasoning by analogy. The reasoning is that by parity of reasoningAmust have the same status asP; and fromParodyof argument - a phrase, albeit somewhat differently used, which I owe to Daniel DennettIntuition pumps and other thinking tools(2013) – this status is an unfortunate one.
This strategy is also similar to the previously mentioned mathematical heuristic of modifying a difficult problem to make it easier. Here we modifyAToPthereby modifying the difficult problem of seeing thatAis unhealthy for the simpler problem to see thatPis unhealthy, which it obviously is. However, unlike the mathematical heuristic, the "proves too much" strategy does not usually involve leavingreturnto the original argumentA, and to diagnose exactly what was wrongEs. It is tarred withP's brush, and that shall be it. It's more like solving the simpler math problem and resting on it. In this respect, the strategy can be unsatisfactory.
From Plato's cave to Singer's "Drowning Child," analogous thinking pervades philosophical thought
Perhaps the most famous example of the "proves too much" technique is the 11th-century Benedictine monk Gaunilo's parody of St. Anselm for the existence of God. According to the concept of God, a greater being is unthinkable. Suppose now that God does not exist. Then a larger beingcouldbe received - one with God's greatnessand who exists.But this is a contradiction: a greater being than God is both unimaginable and imaginable. So we must reject the assumption - that is, we must conclude that God exists. There is an instance ofReduction ad absurdumjustification for you. Gaunilo then parodies it: Consider the concept ofthe perfect island.You can't imagine a bigger island. Now suppose that this island does not exist. Then a bigger islandcouldbe designed - namely one with the size of the islandand that exists. contradiction. So the island exists. But that's absurd. So we should reject the ontological argument that uses parallel arguments - it "proves too much".
"Proves too much" reasoning is a form of reasoning by analogy. Now let's generalize - itself an exercise in such reasoning. Roughly speaking, such reasoning begins by citing similarities between one entity and another; moreover, the latter entity has another feature; one concludes that the former entity also has this feature. Schematic:
Entity X has properties F, G, H, ...
Entity Y also has properties F, G, H and soI.
Therefore (plausibly) entity X also has ownershipI.
The entities can be physical objects like planets or even abstract objects like arguments. The properties can be similarly diverse: for example, being hydrated and life-enhancing or being sick. The "therefore" should be understood as identifying oneinductiveConclusion where the premises are intended to support the conclusion without guaranteeing it (hence the "plausible"). In short, similarity in some respects supports similarity in other respects.
Analogous thinking has played an important role in the history of philosophy. Actually inPhilosophical essays on the human mind(1748) David Hume said (perhaps exaggerating): "All our reasoning of facts rests upon a kind of analogy." From Plato's Allegory of the Cave in theRepublicon Peter Singer's "Drowning Child"Streit, analogous thinking permeates philosophical thinking. But the most famous analogical argument of all is a classic argument for the existence of God.
PPhilosophers speak ofDieDesign argument, but you, careful reader, are questioning the assumption that there is exactly one. And indeed there are many such arguments. I'll present one without claiming it's the best version, but it shows itdifferent heuristicsthat I introduced.
look at a clock You see it's intricate, aesthetically pleasing, and behaves regularly. You also know that it had an intelligent designer. Now look at the world. You see it's intricate, aesthetically pleasing, and behaves regularly. By analogy, you should conclude that it also (plausibly) had an intelligent designer - namely, God. That's the argument. His spirit is captured by the ancient hymn which begins:
All things bright and beautiful
All creatures great and small,
All wise and wonderful
The Lord God made them all...
However, both the argument and the anthem are easy to parody. Check the clock again. Despite its pleasant qualities, it also has shortcomings - it doesn't keep time perfectly, its batteries occasionally need to be replaced, it's easily scratched. So you should conclude that it had afaultydesigners. Now look at the world again. It too has its flaws. Monty Python began cataloging them:
All things boring and ugly
All creatures short and squat,
All things rude and nasty,
The Lord God made the lot...
You should come to the conclusion that the world had one toofaultyDesigners, which is not usually what God is thought to be. Wait! The design argument runs the risk of "proving too much".
InDialogues on natural religion(1779) Hume powerfully parodied a version of the argument from design. He also questioned the supposed resemblance between human artifacts that we know of and the universe; and we have no experience of other universes. In fact, the universe could be considered as oneextremelyIn the case of an entity, and as such quite different from entities like clocks, one can wonder if it could even be causally related, such as when they are created. Finally, Hume asserted that the design argument involves an infinite regression: the intelligent designer, God whose existence the argument purports to support, himself demands explanation and requires a prior intelligent designer. And away we go.
One of the main argumentsagainstthe existence of God isthe problem of evil. (Neon lights!) Consider this version of it:
1. If God had existed, he would have created the best of all possible worlds.
2. Our world is not the best of all possible worlds.
For this reason,
Conclusion: God does not exist.
Here "worlds" are entire universes, and "possible worlds" are ways a universe might be - we might think of them as instances of what is sometimes called the "multiverse".
Premise 1 is said to be plausible for many of the leading conceptions of God—particularly those that portray him as all-good, all-powerful, and all-knowing. (All three properties are necessary for the premise to be plausible - to see why, highlight each of them in your mind and go through the alternatives they oppose.) The premise invites us to imagine different possible worlds to imagine and to imagine how God chooses which of these worlds to create. Premise 2 then compares our world to some of these alternatives. It seems we should treat ourselves, as we can easily imagine that our world is a better place - more happy people, less suffering. (One is reminded of the old joke: an optimist thinks this is the best of all possible worlds; a pessimist fears this is true.)
If God existed, he would have created something. But maybe God exists but didn't create anything?
There are some problems with this argument that our heuristic helps tease out. With the first premise, I hope you've seen "that" in neon lights. Is there exactly one best of all possible worlds? It seems there could be many. For example, start with a best-world candidate and imagine tweaking it in a way that doesn't change its goodness—say, shifting an insignificant particle by a nanometer, or making everything mirror-inverted. At first glance, the result is equally a candidate for the best world. However, the argument in turn could be adjusted accordingly. Just make this premise: “…he would have created itAbest possible world” –likethe candidate. And the similarly adjusted premise 2 looks just as safe: This isn't (even)Abest possible world.
But on the other hand, there seems to be more of a problem: maybe there is a problemNObest of all possible worlds. Rather, worlds can get better and better without end - maybe just a happy person or a happy cow keeps coming. Forget the details of how God could create these better worlds. Any limitation on his ability to do so seems to challenge his omnipotence.
The form of premise 1 is: If God had existed, he would havecreatedsomething. But a relevant alternative is that he may not have created anything at all. Maybe God exists but didn't create anything?
Still, one might insist that he must have it, perhaps as part of the meaning of "God." This brings us to the second premise. Again, notice the contrast here:ourworld, as opposed toOthersworlds. This leads to a different answer: God did not create our world, but He created (instead) the best of all possible worlds. This suggests that the argument is invalid: we can imagine that premises 1 and 2 are true without being committed to the conclusion. Or imagine this godtatcreate the best of all possible worlds; and second best; and the third best... Finally, we come to our world, which is at the bottom of the list, but he created it anyway - perhaps because there's still a balance between good and evil. Again, this suggests that the argument is invalid - just "suggested", mind you; Perhaps it is impossible for one god to create multiple worlds for reasons explained by David Lewis inAbout the plurality of worlds(1986). It presupposes that God faces a world boundary.
Where does that leave us? Well, we have failed to prove the existence of God, nor to prove his non-existence. (I hope you're not too disappointed!) But that goes without saying in philosophy—it rarely proves itselfanythingconclusive. Instead, I hope I've given you a sense of what philosophical thinking is like and how that thinking can be stimulated and improved through the use of various heuristics. Along the way we saw some examples of what followed (or didn't follow) what, uncovered some sophisms, spotted some fallacies, and monitored some of our arguments.
However, the heuristics have their limitations. There are many different skills that make a good philosopher, and I don't pretend to give heuristics for everything philosophers do, or for even a tenth of what they do. In particular, there are no shortcuts to depth, and I should add that good judgment and insight will always come into play - just like in math and chess. However, heuristics can make difficult thinking tasks easier, in philosophy as well as in mathematics and chess.