It has sometimes been argued that philosophy has run its course; yet philosophy continues. They even teach the stuff. It’s an interesting conundrum to reflect upon.
I come to the question with a compound premise that can be expressed in different ways: philosophy isn’t esoteric; it isn’t “irrelevant,” in fact it’s relevant to just about everything, because it’s the study of thought itself – all thought. And (as you know from reading Inside the Liberal Arts) philosophy is where it all started.
The invention of philosophy (a shared enterprise, but one for which Plato deserves the most credit) was the invention of reason in the Western world; and reason is what anchors every other discipline. Reason is intellectual rigor.
Okay – now you know where I’m coming from. There have been two main arguments, as far as I can tell, why philosophy shouldn’t or won’t continue.
One is the idea that all of the great thoughts have already been thought. That is to say, the various possible ways to think about thinking, and about the relation of the mind to the world, to being, to value, etc., are limited and have already been identified.
There’s at least superficial plausibility to that notion. It’s true that there haven’t been many grand philosophical schemes, and none since Hegel and Marx (who, though quite different, bear certain important formal resemblances, as Marx consciously set out to “stand Hegel on his head”).
Before them, Plato and Aristotle, Spinoza and Leibniz and Locke and Hume and Kant came up with what we might call the Big Theories: basic structures for marrying thought and reality. There have been new ideas certainly, and important ones, but none so comprehensive. And most if not all of these Big Theories can be reduced to forms of rationalism (foregrounding reason) and empiricism (forgrounding experience and perception) as rival philosophical frameworks.
It does seem unlikely that another philosopher will appear with something altogether new under the sun, something as radical and original as what those thinkers provided. The gamut from pure reason to radical empiricism seems to have been thoroughly explored. (Kant and others actually bridged them; they were on to something.)
But even if in this sense philosophy has completed its task of organizing our minds at the highest level of abstraction, the job isn’t over, and never will be as long as there is learning. Rising generations still have to learn those lessons anew, have their own debates, and make their own choices. The great questions haven’t all been answered, and many of them are unanswerable or (as a better way to put it) they are answerable in many possible ways, and thus in principle cannot be settled.
A second way of declaring philosophy dead or exhausted was the uniquely audacious claim of a young engineer-turned-logician, Ludwig Wittgenstein, who wandered into philosophy and decided it was all based on linguistic and logical confusions that could be clarified. Philosophy as such, the whole history from the Pre-Socratics onward (with which he was not overly familiar, and which he did not recommend as a course of study) was deemed unnecessary if not mistaken.
Wittgenstein is literally in a class by himself. In the process of trying to demolish philosophy by reducing it to logical or linguistic muddles, he effected the exact opposite result, revitalizing philosophy in the 20th century and beyond. Wittgenstein was wrong, but gloriously so.
Among his many brilliant philosophical insights, the supreme one was the importance of turning language back on itself to think about how we use words. This idea wasn't entirely his own invention; it came out of a tradition among Viennese scholars known as Sprachkritik (critique of language). And earlier philosophers were not all oblivious to the importance of words and their meaning. But he brought it squarely into the domain of philosophy, and in doing so he launched philosophy into the future.
He was right that philosophy has to explore language. He was wrong that that meant the end of philosophy. All critical inquiry begins, but does not end, with careful attention to language. And Wittgenstein isn’t considered the greatest philosopher of the 20th century for having been the last to turn out the lights.
My personal theory (a third explanation for philosophy’s death warrants) is that, in addition to these two bases for declaring philosophy dead, some non-philosophers envy it, sensing that it’s just a tad more trenchant and profound than whatever they are thinking about. They either pretend to be better-versed in philosophy than they actually are, or try to marginalize it. I could be wrong.
Either way, the future will need philosophy, even if (and it’s a big if) no radical new ideas for organizing thought and experience emerge. Philosophy will continue because new architects and new materials and tools can never be ruled out. And it will continue because every generation needs to learn how to think critically, i.e. rationally, i.e. rigorously, and philosophy is the fast-lane to that destination.