The destructive impulse is particularly conspicuous in philosophy. We are forever refuting, criticizing, rejecting, disagreeing, ridiculing, dismantling, tearing down, cutting to pieces, grinding to a fine powder, annihilating, and otherwise smashing to smithereens (or sometimes mildly amending and carefully reformulating). We also construct and create, but a lot of the time our aims are less positive. Why is this? It doesn’t seem to be so in other disciplines, or at least not to the same degree: physicists and biologists don’t spend most of their time ripping each other to shreds, or even correcting and revising what others have to say. They are too busy in the lab or field, discovering things, contributing to human knowledge; but we philosophers always seem to be at each other’s throats. Thus critical acumen is much prized in our field—so-and-so is said to be very “sharp” and a demon with the deft counter-example. Reputations can be built around one “devastating” criticism. Entire philosophies can be primarily destructive: empiricism, positivism, ordinary language philosophy, Wittgenstein in both his periods, Quine much of the time, Berkeley’s idealism, Hume’s skepticism, existentialism, neurophilosophy. There is nothing wrong with that: philosophy really is a highly critical discipline. The whole subject is infused with negativity. Is it because philosophy is so hard? Is it that philosophical problems are so resistant to solution? It’s easier to criticize than to construct, destroy rather than create. We are frustrated by our chosen subject, but we can at least vent our frustrations in bouts of mutual destruction, otherwise known as civilized debate. This can be enjoyable enough, thrillingly ego-driven, and even fairly amusing—better than banging your head against a brick wall. I get a kick out of it anyway. The predominant feeling you have when trying to construct something in philosophy is a sense of vulnerability: someone is going to destroy what you have struggled to create, undermining your carefully constructed arguments, and gutting you intellectually. This is not a fun feeling; better to rip into someone else and watch the feathers fly. Yes, it’s faintly discreditable, a bit of a cop-out, but at least you are achieving something with your time (that arduous education has not gone completely to waste). Or you could just become an historian.
But let us analyze the destructive impulse in philosophy further: what is philosophical destruction? What are you aiming to do, and for what purpose? The OED puts us on the right track (as always): “destroy” is defined as “put an end to the existence of (something) by damaging or attacking it”. We are informed that the English word derives from an Old French word destruire, which is constructed from de expressing reversal and struere meaning “build”. Thus “destroy” literally means, “de-build”. It is like “depopulate” or “desegregate” or “deactivate” or “deconstruct”. This suggests that you cannot destroy what has not been built (though that concept is quite flexible and is not limited to human artifacts): it sounds funny to speak of destroying a heap or a wreck or a mess or even a random chunk of rock—for none of these things bespeaks constructive purpose. You primarily destroy what has been created, generally with a purpose in mind: human artifacts, human lives, animals, plants, buildings, systems of thought, arguments. Destroying is the opposite of building. Also, according to the dictionary, it involves two elements: existence and damaging by attacking. First, the thing destroyed has to exist: you can’t destroy what has no existence (fictional characters, hallucinated rabbits, meaningless jumbles of words). Second, the destruction (the “putting out of existence”) is accomplished by means of an aggressive act—attacking and damaging. This latter point is important: there is no avoiding the involvement of violence in philosophical criticism. You can’t destroy (demolish, decimate) an argument or a position without doing violence to it—as you can’t destroy a material object without doing violence to it. We may as well own up to this and not pussyfoot around: philosophical destruction is inherently aggressive, necessarily a form of attack (not on the person, of course, but on the position being destroyed). The aim is to put that position out of existence, i.e. refute it—overtly and publicly. Ultimately this means that we want to destroy belief in that position: we want to take existent beliefs and put them out of existence. That is what it is to put a philosophical position out of existence—to destroy belief in it. If I am trying to refute a certain position, I am aiming to destroy whatever belief others may have in that position: I am trying to eliminate a part of the other’s mind, or a component of his or her mental state. This is why it is apt to speak of destruction in connection with philosophical (and other intellectual) criticism: criticism is not intended to leave your mind unchanged, your beliefs happily intact. Let me be a touch melodramatic: refutation is murdering beliefs—putting them out of commission, consigning them to the Big Sleep. It is outright belief annihilation.  So there is always something pugilistic and gladiatorial at play in philosophical disputation: a life is at stake, namely the life of the participants’ beliefs (opinions, commitments). Something is liable to go out of existence during a philosophical argument. No wonder there is resistance, tension, risk, fear, self-defense, and an atmosphere of combat: something’s very existence is at stake, often beliefs that have taken a lifetime to arrive at (all that work and puff!). We can also note that there is something godlike about the activity: the creative artist is often compared to God on account of her ability to bring things into being apparently from nowhere, but the power to destroy is also a feat of existence alteration—putting things out of existence. God has this power too, in abundance, and we humans can exercise it ourselves in more limited ways. No doubt the literal murderer relishes exercising this awesome power. Just so the philosophical “murderer” can relish his power to destroy positions and belief in them: look how I just annihilated that poor shmuck’s position! We humans have power over existence (as existence has power over us) and philosophical creation and destruction partake of that power. Don’t you think the positivists relished the destructive power of their philosophy? They put those babbling metaphysicians to the guillotine! They didn’t have much constructively to put in its place (the dirty little secret of positivism), but they could certainly do a tremendous amount of damage to existing belief. Their weapon of choice was the verification principle: wielding this sharp-edged sword they could cut traditional philosophical thought to pieces. It was a rotting zombie anyway, in their considered opinion, so it may as well be put out of its misery. On a lesser scale of destructive euphoria, we have the work of Strawson on Russell’s theory of descriptions, Quine’s “Two Dogmas of Empiricism”, Gettier on the analysis of knowledge, Kripke on the description theory of names, and Grice on conversational implicature—to pick some examples pretty much at random. And there is nothing in principle wrong with such destruction (or purported destruction)–with such aggression and annihilation; as I remarked, it is an essential part of philosophy. Philosophy is supposed to be destructive (though not only destructive). 
And here we run up against a further category of philosophical destruction (perhaps my personal favorite): destroying the destroyer. The positivist gunman swaggers into town ready to do some serious destroying: in his sights lie all traditional metaphysics, much of morality, and a good deal of science. Then the wily sheriff (silent, gruff) steps nimbly forward to stem this tide of destruction, revealing the blustering stranger as a fake and a wimp—a no-account loud-mouthed nobody. His draw is slow and his aim shaky: he gets handily refuted before he can do much damage (though there was that unfortunate business with the town drunk in the saloon, poor old Jeb). This is what was so gratifying about Grice on implicature and Kripke on necessity: they destroyed the would-be destroyers. They wielded superior weapons and exhibited superior skills, and the opposition went down. In so doing they resurrected ideas deemed extinct, bringing traditional questions back to life. For it is never a happy moment when a philosopher kills off an idea that doesn’t deserve that fate; and we welcome the savior who restores to life what had been thought extinguished for good. Even the problem of consciousness has been thought extinguished, only to come roaring back to life once certain misguided ideas have been exploded. So we must always be on the lookout for opportunities to reverse previous acts of wanton destruction (or alleged destruction). I would say the same for a lot of what Wittgenstein has been thought to have terminated; ditto for Quine. So I particularly relish the dismantling of such would-be destroyers. Destruction sometimes needs to be destroyed in turn.
We should distinguish two sorts of destructive philosophical act: destroying existing philosophical theories and destroying common sense (or possibly parts of accepted science). Philosophers are generally perfectly comfortable with the first sort of destruction, but the second is regarded as far more problematic. Preventing commonsense belief from destruction may involve destroying the arguments of anti-commonsense philosophers. It is, of course, controversial what counts as part of common sense (Berkeley’s idealism being a famous case), but we usually know if commonsense belief is being criticized. Overtly nihilist positions are typically destructive of common sense, intentionally so: asserting that nothing exists must surely count as destructive in this way. This is the analogue of destroying noncombatants in a war: other philosophers are soldiers in wars of mutual destruction, but ordinary folk are the equivalent of peaceful civilians. They are more likely to be invoked in the battle against opposing philosophers than made victims of destruction themselves. Scorched earth tactics against civilians are not most philosophers’ style, while the belief systems of other philosophers are considered fair game. If you go into philosophy, this sort of aggressive action is only to be expected. You can avoid it only by not sticking your neck out, possibly limiting yourself to destructive philosophy and never venturing anything constructive of your own (though you must cover yourself against destroyer destroyers). Frege is a good example of a philosopher who does the opposite: though he certainly offers criticisms of positions he is against (e.g. psychologism), he mainly tries to construct something positive. He erects an impressive edifice, systematic and precise, thus exposing his creation to possible destructive criticism (Russell’s paradox was surely a heavy blow). He is perhaps the most constructive analytical philosopher ever. Wittgenstein, by contrast, is relatively destructive. Russell lies somewhere in between. Quine is largely destructive, with occasional gleams of creativity. Kripke is a bit of both. Socrates was entirely negative. Plato and Aristotle leaned positive. And so on: each philosopher in the canon can be considered as a destroyer or as a creator. I myself am quite fond of a bit of philosophical destruction, but I also have a weakness for construction—so I am well aware of destructive efforts aimed in my direction (again, nothing wrong with that). 
What are the devices of philosophical destruction, its techniques and technology? They are well known to the trained philosopher: the detection of fallacies, the exposure of non-sequiturs (both subtle and gross), producing counterexamples, exposing use-mention confusions and type-token errors, and so on. With these weapons we carry out our destructive work, and valuable work it is. Logic is best seen in this light: it is a device of destruction, the equivalent of a deadly weapon of war. It isn’t used much for constructive purposes (not counting logicism and ascriptions of logical form), but it is the bread and butter of discursive demolition. Logic is what we wield when we set about demolishing a position—its main purpose is destructive. It is concerned with exposing logical fallacies rather than constructing logical arguments; its function veers negative. It is all about what does not follow. This should be built into the way logic is taught: it is a machine for winnowing out faulty reasoning. It isn’t a method for having new ideas but a device for destroying existing ideas (bad ones). I mean this in a broad sense of “logic”—not just propositional and predicate calculus but informal logic too (also induction and abduction). Logic is concerned with evaluating reasoning, and evaluation implies criticism, which implies destruction. Accusing someone of begging the question, say, is a destructive act: what the speaker just said has been reduced to rubble. Again, we should not pussyfoot around about this: philosophical expertise is like the expertise of a demolition man—both are good at destroying buildings, physical or intellectual. Both do valuable work, by clearing sites of rickety old buildings so that new ones can replace them. Philosophical destruction, recognized as such, is nothing to regret or feel ashamed of. It is the engine of truth. 
 There are echoes of Popper’s “critical philosophy” here—the emphasis on refutation and falsification instead of verification. Popper thinks that scientific progress occurs mainly by a process of elimination, much like natural selection: we don’t proceed by confirming good theories but by falsifying bad ones. Destruction of accepted theories is thus the engine of scientific advance. We might call this “discovery by destruction”. Philosophy, for a Popperian, is similar: the elimination of theories that fail to stand up to criticism. The counterexample is the engine of philosophical advance. Aggressive criticism is the means of achieving philosophical truth.
 Let me indulge in a medical analogy: it is part of medicine to destroy pathogens, the better to improve health. This destruction is essential to medicine and not at all sinister. Wittgenstein compared philosophy to therapy, which emphasizes improvement on the part of the patient; but he never explicitly drew attention to the point that destruction can also be part of the process (though he was himself flagrantly destructive). In fact, even Freudian psychotherapy has a destructive component, since harmful neuroses and repressions need to be destroyed (talking was supposed to do that). Isn’t psychiatry really concerned with the destruction of mental illness, using drugs, ECT, brain surgery, behavioral modification, and what- not?
 If I ask myself what are my favorite examples of philosophical destruction, the answer comes back: Frege’s criticism of Mill’s theory of numbers, and Leibniz’s criticism of Locke’s theory of ideas. And who could not love Chomsky’s demolition of Skinner’s Verbal Behavior (though this is not strictly philosophy)? These all contributed massively to human thought.
 Of course, there is a psychology and sociology of intellectual destruction in academic culture that can only be described as deplorable. I cannot even bring myself to discuss this lamentable subject. Its chief defect is confusion(the harshest word in my vocabulary).