Final answer:
Quintilian's philosophy emphasizes the technical aspects of speaking and effective oratory, while Socrates and Plato emphasize the search for truth through dialectical reasoning over rhetorical persuasion.
Step-by-step explanation:
Quintilian's philosophy of rhetoric is distinct from that of Socrates and Plato primarily in its practical and educational emphasis on the art of speaking and persuasion, particularly in public oratory. Quintilian focused on the technical aspects of speaking, such as posture and gesture, which can be seen in his Institutes of Oratory, where he discusses the importance of the speaker's physical presence and movements to make an impact on the audience. Contrastingly, Socrates and Plato criticized the Sophists for similar focus on rhetoric, arguing instead for the pursuit of truth through the dialectical process, which involves back-and-forth reasoning and questioning to arrive at deeper philosophical truths, rather than simply convincing an audience through appeal to emotion or memorized statements.