Asides from a search for the truth for its own sake it appears that philosophy is motivated in two other ways: for utility and for guidance. Utility is fairly self-explanatory but by it I mean pursuit of knowledge that can benefit our lives. By guidance I mean grounding what it even means for something to be of benefit. Guidance on questions of purpose, ethics and goodness; what our lives should be rather than simply how to attain this undefined ‘ought.’
Natural Philosophy (incorporated by the sciences) seems talented in its task at providing Man the things it desires and giving accounts of the natural order of the world. The development of ethics however, is not as clear as the natural sciences however because it deals with what cannot be easily verified through an instrument. It deals with ideas of living that are personal and controversial, but it is these matters of what human nature is and how we are to live that makes any descriptive account of the world relevant. Describing what is is not of significance if we do not know what is significant – what ought to be.
If philosophy exists in order for us to gain knowledge of this world and for us to live well in it then further endeavor in epistemology is no longer necessary and exploration of metaphysics (in the strictest sense) never was. David Hume and those who follow in his notions of knowledge, idea formation and probability have provided an account of knowledge which has aided great minds in providing things of great utility (among other possibilities) to the human race.
If we examine the fields of knowledge, we find that broadly speaking the whole can be segmented into two: knowledge of physical properties and knowledge of sentient beings. This is not accepting Metaphysical Dualism despite its superficial similarity. Instead, if we examine what men have learned throughout the centuries, it seems we have learned a great deal in regards to the properties bodies and substances appear to have and how to manipulate the physical order in order to attain our goals.
How to attain the desired behavior(s) out of men and women and what even this desired conduct is however remains if not a mystery of philosophy then a failure in action and realization – for everyone despite their disagreements would agree that much of the world is not as it ideally would be. If philosophy is to be practical it need go no further in the realm of bodies, for science seems to be doing its proper role in a way that the philosophers of centuries past could scarcely imagine. Most would argue however that there is far more to alter in regards to ethics and politics (human conduct and organization) to achieve desirable conditions for humans and other inhabitants of the biosphere.
Though we need knowledge of ‘oughts’ to have any knowledge be of consequence, we also need knowledge of descriptive particulars for that knowledge to be of any use. Practical wisdom entails knowing what is and what is achievable in what ought to be. That is, it is an inherently pessimist account of “making the best of the non-best situation.” Knowing we will never reach the ideal, but instead knowing the world, what is desirable and striving what is achievable or possible in the world rather than acting on the ideal (normative accounts) alone. This is what religions are known to do which is why they often can achieve very little of their goals. They are talented at achieving their political goals but not the ultimate ends of universal belief and goodness, because what they strive for is not only impossible but they make no legitimate attempts at attaining it.
 True, it by no way follows through the strictest reasoning that simply because all think the world is not ideal that the world is not ideal – everyone could be wrong. But it does follow logically if we provide the normative claim that the world should resemble something that most people are content with as opposed to a world of suffering, randomness and injustice.