"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."