Arguments of circumstance, according to Weaver, involved the current circumstances as the basis for argument, and were at the bottom of his ethical totem-pole. At the other end, obviously, are located his arguments of definition, which deal with the classification of permanent universals and essences, and the order of these is to be determined by the virtue and purity of the argumentation. In his essay, Language is Sermonic , Weaver understands that the use of the scientific and logical is necessary in establishing an argument, but that rhetoric is not solely based on the rational or the scientific. We are human, and to be human includes sides of us that are not rational, and there are definitions that cannot be completely encompassed by the rational. With this in mind, Weaver states that the appeal to the emotional, or ethos, is a key element to the most ethical of debates, and because of this he stresses the importance of morals and nobility in speech when dealing with rhetoric.
Emotions are very powerful tools, and when used in rhetoric, they can sway opinions and beliefs.
If they are abused, it is no minor offense. Furthermore, to employ dubious tactics in an argument of definition, it is to effect permanent and unchanging properties, a weighty felony. King begins by unifying his audience, recalling the great injustices that have been carried against the blacks of America, and in the fourth paragraph he identifies the offense of having equality laws in a country so tainted by racism and prejudice. Throughout his speech King decrees his personal vision of an ideal nation where people of all colors could unite and live together harmoniously. His speech exemplifies Weavers concept of maintaing an ethical and noble cause behind your rhetoric, and unlike Quintilian, Weaver makes no allowances for moral relativism, and neither does King, for his speech argues the ideal the whole time, and never once does he enter into a treatise of morals or ethics.