Definition and Examples of Pistis in Classical Rhetoric

In classical rhetoric, pistis can mean proof, belief, or state of mind.

"Pisteis (in the sense of means of persuasion) are classified by Aristotle into two categories: artless proofs (pisteis atechnoi), that is, those that are not provided by the speaker but are pre-existing, and artistic proofs (pisteis entechnoi), that is, those that are created by the speaker."
A Companion to Greek Rhetoric, 2010

Etymology: From the Greek, "faith"

Observations

• P. Rollinson
  The opening [of Aristotle's Rhetoric] defines rhetoric as the 'counterpart of dialectic,' which seeks not to persuade but to find the appropriate means of persuasion in any given situation (1.1.1-4 and 1.2.1). These means are to be found in various kinds of proof or conviction (pistis). . . . Proofs are of two kinds: inartificial (not involving rhetorical art—e.g., in forensic [judicial] rhetoric: laws, witnesses, contracts, torture, and oaths) and artificial [artistic] (involving the art of rhetoric).
  
• Daniel Bender
  One aim of speech within a Western rhetorical tradition is to produce pistis (belief), which will, in turn, produce consensus. A student trained to imitate models, to speak in different ways, could conform language and reasoning to the capacities of different audiences, and thus create that consubstantiality between speaker and audience, the rhetorically created scene of community.
  
• William M. A. Grimaldi
  Pistis is used to represent the state of mind, namely, conviction or belief, at which the auditor arrives when the correctly chosen aspects of the subject-matter are placed before him in an effective manner. . . .
  "In its second meaning, pistis is the word used for a methodological technique . . .. In this sense, pistis means the logical instrument used by the mind to marshal the material into a reasoning process. It is a method which gives the matter a logical form, so to speak, and thus produces that state of mind in the auditor which is called belief, pistis. . . . It is this meaning of pistis which is applicable primarily to enthymeme, but also to paradeigma (example). For in rhetoric enthymeme (the process of deduction) and paradeigma (the inductive process) are the logical instruments which one is to use in constructing argumentation directed toward krisis, or judgment, on the part of another.