Rhetoric interferes when it builds illusions. Linking ideas to reveal similarities. Abstraction of ideas. Addition, subtraction, combination and arrangement help us build complext ideas from simple ones. C. Locke thereby revives audience adaptation arguing that rhetoric is the application of reason to the imagination for the better moving of the will.
Internal discourse is more authentic because it is more likely to be based on direct apprehension.
External discourse is more likely to be corrupted because it is adapted to society, culture, and ordinary language. Challenge is to cleanse internal discourse, and then cleanse external discourse. We must communicate to clarify our ideas and to be sure we are not tyrranized by the language of others. Locke, like Newton and Bacon, ushered in the Enlightenment in which men believed that science and logic could solve all problems. That mutual agreement among the educated could verify truth.