On Great Philosophers

It seems throughout history their were a few minds that changed its course, we can think of Plato, Socrates, Aristotle, Descartes, Kant. How does it come that they rise so far above "the common rabble?" What makes them so great? The biggest thing that they seem to have in common is that they were not afraid to ask tough questions and they didn't just stop at someone else's answer. Two common things seemed to drive these philosophers (especially the first two) and those two things are truth and morality. Some, like Descartes were more seekers of truth and others like Kant were more seekers of morality, but every one of those philosophers studied both. So what is truth and what is morality and how are they related? Truth is the idea that the ideas we have about the world 'in our head' match up with the ideas 'in the world.' Morality seems to be the idea that we act so as to increase some sort of good thing and decrease some sort of bad thing. But why are these concepts so important to philosophers? It seems that wanting to increase good things and decrease bad things is so natural it needs not an argument but just an understanding of language. Morality defines what those good and bad things are and truth sets out ways in which one knows the results of ones actions. If one knows the truth and has a good system of morality, all they have to do is implement it and the world will be better. Thus we come to the final thing that separates the greatest from "the common rabble" and that is will, the will to implement good intentions to turn them into reality. But, why do I put the common rabble in scare quotes, it is because anyone, if given the opportunity can rise above the common rabble, yet they are the common rabble--the greatest philosophers do not overcome the world, they overcome themselves.