I recently ran across and interesting quote concerning the differences between philosophy and rhetoric as orientations for viewing the world from George Kennedy:
The disagreement between Plato and the sophists over rhetoric was not simply an historical contingency, but reflects a fundamental cleavage between two irreconcilable ways of viewing the world. There have always been those, especially among philosophers and religious thinkers, who have emphasized goals and absolute standards and have talked much about truth, while there have been as many others to whom these concepts seem shadowy or imaginary and who find the only certain reality in the process of life and the present moment. In general, rhetoricians and orators, with certain distinguished exceptions, have held the latter view, which is the logical, if unconscious, basis of their common view of art as a response to a rhetorical challenge unconstrained by external principles. The difference is not only that between Plato and Gorgias, but between Demosthenes and Isocrates, Virgil and Ovid, Dante and Petrarch, and perhaps Milton and Shakespeare.
Coastal Writing 