"Know thyself, presume not God to scan, The proper study of Mankind is Man." So wrote Alexander Pope, whose fondness for couplets may lead some to think of him as a kind of proto-rapper, if it is possible to think of a rapper as being like Pope--someone with an actual talent for poetry who did not, so far as we know, recite his rhymes while hopping about and gesticulating for what would no doubt have been a very bewildered audience.
"Know thyself" we are told were words inscribed at the temple of Apollo at Delphi, along with "nothing in excess." These words are sometimes ascribed to philosophers, such as Socrates, and if they were not those of Apollo they may as well be his, or Plato's or someone else. Also ascribed to many philosophers is the tendency to presume to scan God, and other things which Pope likely thought were not proper studies of mankind, if Man is that study.
Sadly, perhaps for those who read this as well as for me, I feel called upon to complain once more of the fact that the philosophically inclined seem intent on ignoring the problems of humans in the world, i.e. the problems people encounter while living in the world, and instead address problems, if they can be called problems, which appear to have little to do with living in the world--and the less, the better. I imagine perhaps without good cause that those who concern themselves with debating such issues as whether God exists, or others exist, or the universe exists, or whether there is such a thing as free will, the problem of induction....all the matters which have been the subject of debate for centuries among philosophers, would do humanity a service if they started considering with the same intensity matters such as the allocation of dwindling resources, the elimination of poverty, the manner in which to resolve disputes among nations, education, even how to behave in a manner which will not result in harm to others. But I may well be considered odd, even annoying and obstructive, for doing so. The "problems of philosophy" hold such a fascination that it may be that those who concern themselves with them cannot become unconcerned with them.
Now, it's quite possible that I'm simply wrong. I may be unduly optimistic. Perhaps philosophers don't have much to add to the resolution of the pressing problems of life. It would seem to me, though, that compared to the politicians and pundits we entrust with their resolution, philosophers would do quite well. Philosophers actually know how to think, and write; things it is not clear either politicians or pundits can do for an extended period.
I recently read Schopenhauer's The Wisdom of Life. Although I'm not enthralled by his philosophy, I was pleased by the thought that he would write a book on practical wisdom. It even has the word "Life" in its title. I was disappointed, though, to find it to be a kind of collection of banalities. He's careful to note that this little book is not representative of his philosophy, but then in describing how best to live he simply repeats some stoic essentials, makes the hardly surprising or interesting point that intellectual pleasures are best, and refers frequently to the ways in which "common people" are wrong in what they find good. Schopenhauer clearly doesn't care much for the common people, and spends a good deal of space noting their various inadequacies. He quotes liberally from the ancients and also Goethe, for good measure. His condemnation of the practice of duelling is historically interesting, though.
It's also true that those philosophers who have concerned themselves with real life problems sometimes have been wildly absolute and persuasively and very influentially wrong in their conclusions. Plato's view of the ideal state is frightening. Ancient philosophers (as well as the Bible) were relied on by those who sought to justify slavery (Aristotle thought there were those who were born to rule, and those who were born to be ruled). Heidegger thought Hitler and the Nazis would lead Germany and the world to some sort of inexplicable, mystic kind of paradise for some inexplicable, mystic reasons.
But the argument can be made that these philosophers came to often repulsive conclusions regarding the problems of life because they were led to do so inexorably by the conclusions they arrived at in the otherworldly, decidedly inhuman realm of traditional philosophy, so disassociated from the problems of living. And, having thought that they had arrived at absolute truths in this detached realm, they felt that all they need do in addressing the problems of the real world is apply those truths, regardless of their effects.
So, perhaps if philosophers stopped dealing with the "problems of philosophy" they would not make such mistakes in dealing with the problems of humans.