Bertrand Russell writes (about Plato's political philosophy):
Two general questions arise in confronting Plato with modern ideas. The first is: Is there such a thing as "wisdom"? The second is: Granted that there is such a thing, can any constitution be devised that will give it political power?
"Wisdom," in the sense supposed, would not be any kind of specialized skill, such as is possessed by the shoemaker or the physician or the military tactician. It must be something more generalized than this, since its possession is supposed to make a man capable of governing wisely. I think Plato would have said that it consists in knowledge of the good, and would have supplemented this definition with the Socratic doctrine that no man sins wittingly, from which it follows that whoever knows what is good does what is right. To us, such a view seems remote from reality.That seems right. As does this:
It should be observed, further, that the view which substitutes the consensus of opinion for an objective standard has certain consequences that few would accept. What are we to say of scientific innovators like Galileo, who advocate an opinion with which few agree, but finally win the support of almost everybody? They do so by means of arguments, not by emotional appeals or state propaganda or the use of force. This implies a criterion other than the general opinion. In ethical matters, there is something analogous in the case of the great religious teachers. Christ taught that it is not wrong to pluck ears of corn on the Sabbath, but that it is wrong to hate your enemies. Such ethical innovations obviously imply some standard other than majority opinion, but the standard, whatever it is, is not objective fact, as in a scientific question. This problem is a difficult one, and I do not profess to be able to solve it.The first of these passages raises a question about what a philosopher might be. Surely not a lover of wisdom if wisdom does not exist. The first sentence of the second passage points out that the consensus of opinion is against the idea that the consensus of opinion is the standard of truth/rightness (i.e. the idea that I think of as relativism). In other words, as is well known, simple relativism undermines itself.
Rejecting platonism in favor of something like relativism leads to the idea that there is a standard other than majority opinion, but not an objective fact of the kind found in science. I think this is right. And it suggests also that philosophy is, or at least perhaps might be, the teasing out of this kind implication and the clarification of its not being an instance of various kinds of mistake (such as platonism and relativism) despite appearances to the contrary. This "something like relativism" rejects views that "seem to us remote from reality" and that "few would accept." Not in a superficial way though. It does not, for instance, simply take platonism and then substitute the consensus of opinion for an objective standard. That would lead to a conservatism that few would accept. Instead it investigates our language from the inside, looking not so much at opinions as they might be reported to outside observers but at what we say and would say. And we can know what we would say because the 'we' in question includes us. Of course sometimes we might be divided, and then one can only speak for those who think like oneself, but this need not be a big problem in many cases.
This is what I mean when I say that relativism properly thought through leads to ordinary language philosophy. I can't say that I have properly thought this through myself, though, so I could be wrong. Or it might have been said much better long ago. Or both.