The best reason for a revival of philosophy is that unless a man has a philosophy certain horrible things will happen to him.  He will be practical; he will be progressive; he will cultivate efficiency; he will trust in evolution; he will do the work that lies nearest; he will devote himself to deeds, not words.  Thus struck down by blow after blow of blind stupidity and random fate, he will stagger on to a miserable death with no comfort but a series of catchwords; such as those which I have catalogued above.  Those things are simply substitutes for thoughts.  In some cases they are the tags and tail-ends of somebody else’s thinking.  That means that a man who refuses to have his own philosophy will not even have the advantages of a brute beast, and be left to his own instincts.  He will only have the used-up scraps of somebody else’s philosophy; which the beasts do not have to inherit; hence their happiness.  Men have always one of two things: either a complete and conscious philosophy or the unconscious acceptance of the broken bits of some incomplete and shattered and often discredited philosophy.  Such broken bits are the phrases I have quoted: efficiency and evolution and the rest.  The idea of being “practical”, standing all by itself, is all that remains of a Pragmatism that cannot stand at all.  It is impossible to be practical without a Pragma.  And what would happen if you went up to the next practical man you met and said to the poor dear old duffer, “Where is your Pragma?” Doing the work that is nearest is obvious nonsense; yet it has been repeated in many albums.  In nine cases out of ten it would mean doing the work that we are least fitted to do, such as cleaning the windows or clouting the policeman over the head.  “Deeds, not words” is itself an excellent example of “Words, not thoughts”.  It is a deed to throw a pebble into a pond and a word that sends a prisoner to the gallows.  But there are certainly very futile words; and this sort of journalistic philosophy and popular science almost entirely consists of them.

Some people fear that philosophy will bore or bewilder them; because they think it is not only a string of long words, but a tangle of complicated notions.  These people miss the whole point of the modern situation.  These are exactly the evils that exist already; mostly for want of a philosophy.  The politicians and the papers are always using long words.  It is not a complete consolation that they use them wrong.  The political and social relations are already hopelessly complicated.  They are far more complicated than any page of medieval metaphysics; the only difference is that the medievalist could trace out the tangle and follow the complications; and the moderns cannot.  The chief practical things of today, like finance and political corruption, are frightfully complicated.  We are content to tolerate them because we are content to misunderstand them, not to understand them.  The business world needs metaphysics — to simplify it.
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Philosophy is merely thought that has been thought out.  It is often a great bore.  But man has no alternative, except between being influenced by thought that has been thought out and being influenced by thought that has not been thought out.  The latter is what we commonly call culture and enlightenment today.  But man is always influenced by thought of some kind, his own or somebody else’s; that of somebody he trusts or that of somebody he never heard of, thought at first, second or third hand; thought from exploded legends or unverified rumours; but always something with the shadow of a system of values and a reason for preference.  A man does test everything by something.  The question here is whether he has ever tested the test.

­—G.K. Chesterton, The Common Man, The Revival of Philosophy—Why?

It is, indeed, a problem that so many people have never put so much as a few minutes thought into their idea of what the world that they live in is and what are the things that they find in it. One runs into this constantly.

It is not new, of course. It is merely more obvious at present. It’s more obvious because modern cultures do not have any dominant philosophy of life and so unthinking people do not have that accidental consistency which can give the misimpression that they believe consistent things. Each “used-up scrap of somebody else’s philosophy” comes, in modern times, from a different somebody else, which makes this lack of understanding of what he is saying far more obvious.

Which is not to say, of course, that there never was a time and place where it was more common for people to be taught to think and actually do a little bit of it. One of the effects of modern culture being a muddle of many different people’s philosophies is that it discourages a great many people from doing any thinking, just as a storm discourages a great many people from going outside.

It is worth noting, though, that human beings have tendend toward not thinking rigorously since the fall of man. Times and places vary with how much people actually bother to think, but they var far more with how obvious it is that they haven’t.