The concept of warrant reflects Toulmin\u27s general insights that validity in reasoning comes in many forms, and that reasoning in most fields cannot possess the necessity and certainty characteristic of the \u27Rationalist\u27 paradigm. However, there is a scarcity of concepts in one part of Toulmin\u27s theory of argument. While the pedagogical applications of Toulmin\u27s model offer a fine-grained system of warrant types for propositions (sign warrants, causal warrants, etc.), they have only one category of warrant for practical claims (proposals for action) – the \u27motivational\u27 warrant. Fortunately, ancient rhetorical thinking can help us correct this insufficiency. For example, the author of the rhetorical textbook used by Alexander the Great proposed a typology of practical warrants. His approach highlights what I propose to call the \u27multidimensionality\u27, and hence what modern moral philosophers call the \u27incommensurability\u27 of warrants – the absence of a common measure allowing for a \u27rational\u27 balancing of conflicting warrants. The widespread occurrence of multidimensionality in practical argument lends support to Toulmin\u27s general anti-rationalist view of reasoning. Moreover, while multidimensionality prevents \u27rational\u27 balancing, it legitimizes and even necessitates the use of rhetoric in practical reasoning
