If philosophy aims at being a theoretical mode of thought and speech, can it have a rhetorical character and be expressed in rhetorical forms? The answer seems obvious. Theoretical thinking, as a rational process, excludes every rhetorical element because pathetic influences—the influences of feeling—disturb the clarity of rational thought. …
To prove means to show something to be something, on the basis of something. To have something through which something is shown and explained definitively is the foundation of our knowledge. Apodictic, demonstrative speech is the kind of speech which establishes the definition of a phenomenon by tracing it back to ultimate principles, or archai. It is clear that the first archai of any proof and hence of knowledge cannot be proved themselves because they cannot be the object of apodictic, demonstrative, logical speech; otherwise they would not be the first assertions. Their nonderivable, primary character is evident from the fact that we neither can speak nor comport ourselves without them, for both speech and human activity simply presuppose them. But if the original assertions are not demonstrable, what is the character of the speech in which we express them? Obviously this type of speech cannot have a rational-theoretical character. ...
Basic premises cannot have an apodictic, demonstrative character and structure but are thoroughly indicative. ... Arche … cannot have a rational but only a rhetorical character. Thus the term "rhetoric" assumes a fundamentally new significance; "rhetoric" is not, nor can it be the art, the technique of an exterior persuasion; it is rather the speech which is the basis of the rational thought.
According to the traditional interpretation Plato’s attitude against rhetoric is a rejection of the doxa, or opinion, and of the impact of images, upon which the art of rhetoric relies; at the same time his attitude is considered as a defense of the theoretical, rational speech, that is, of episteme. The fundamental argument of Plato’s critique of rhetoric usually is exemplified by the thesis, maintained, among other things, in the Gorgias, that only he who "knows" [epistatai] can speak correctly; for what would be the use of the "beautiful," of the rhetorical speech, if it merely sprang from opinions [doxa], hence from not knowing? … Plato’s … rejection of rhetoric, when understood in this manner, assumes that Plato rejects every emotive element in the realm of knowledge. But in several of his dialogues Plato connects the philosophical process, for example, with eros, which would lead to the conclusion that he attributes a decisive role to the emotive, seen even in philosophy as the absolute science.
In the second part of the Phaedrus Plato attempts to clarify the nature of “true” rhetoric. … it does not arise from a posterior unity which presupposes the duality of ratio and passio, but illuminates and influences the passions through its original, imaginative characters. Thus philosophy is not a posterior synthesis of pathos and logos but the original unity of the two under the power of the original archai. Plato sees true rhetoric as psychology which can fulfill its truly “moving” function only if it masters original images [eide]. Thus the true philosophy is rhetoric, and the true rhetoric is philosophy, a philosophy which does not need an “external” rhetoric to convince, and a rhetoric that does not need an “external” content of verity.
We are forced to distinguish between three kinds of speech: (1) The external, “rhetorical speech,” in the common meaning of this expression, which only refers to images because they affect the passions. Since these images do not stem from insight, however, they remain an object of opinion. This is the case of the purely emotive, false speech: “rhetoric” in the usual negative sense. (2) The speech which arises exclusively from a rational proceeding. It is true that this is of a demonstrative character, but it cannot have a rhetorical effect because purely rational arguments do not attain to the passions, i.e., “theoretical” speech in the usual sense. (3) The true rhetorical speech. This springs from the archai, nondeductible, moving, and indicative, due to its original images. The original speech is that of the wise man, of the sophos, who is not only epistetai, but who with insight leads, guides, and attracts.
The general opinion … is that the humanist tradition is primarily of literary and aesthetical significance rather than of philosophical significance. This view has its origin in statements of Descartes.
If Descartes’ main aspirations are directed towards a “first truth,” it follows necessarily that the sphere of pure possibilities, and with it the sphere of “probability,” is excluded from philosophy. Thus Descartes ignores, for example, both the art of rhetoric and history, as fields in which “the probable,” rather than the truth prevails.
The art of eloquence belongs to the realm of probability because it constantly directs its glance at the specific, variable psychic state of the audience.
The defects of rationalistic, critical philosophy are much more important than they appear at first sight. By failing to take into account political faculties and the art of eloquence, this philosophy disregards two of the most important branches of human activity. … Vico formulates this idea clearly in De studiorum ratione: “But this order of studies brings with it the disadvantage for young people, that in the future they will neither show intelligence in civil life, not be able to enliven a speech with characteristic colors and warm it with the fire of emotions.”
Vico claims that the aim of philosophy is the problem of "finding," and he identifies the theory of "finding" with "topical philosophy.” …
In Quintilian’s expositions there appears a note of melancholy when he discovers that toward the decline of life, the ratio sneaks in gradually, choking up insight into the original.