n Greek, logos translates into
"word" or "reason". In rhetoric, logos refers to systems of reasoning.
Logos, along with ethos and pathos, make up means of persuasion called pisteis,
or kinds of appeals effecting an audience (Covino & Jolliffe 15).
Aristotle, also known as "The Father of Logic," was the first philosopher to create the three textual appeals of pisteis (World Book 381; Covino & Jolliffe 15). In Rhetoric, he describes logos as thought manifested in speech (Covino & Jolliffe 64). He also compiled his works on knowledge in Organon, which means instrument, because it investigates thought, the instrument of knowledge (World Book 627). It includes The Categories, The Prior and Posterior Analytics, The Topic, and On Interpretation (World Book 627). Different philosphers have had many different perceptions of logos over the centuries. In Encomium of Helen, the sophist Gorgias refered to the power of logos as magical and that diabolical forces reside in words (Covino & Jolliffe 64). A 6th century Greek philosopher, Heraclitus, thought of logos as the ordering principle of the universe that stands for divine reasoning (Covino & Jolliffe 64). This Greek thinking opened philosophy for others to follow (Heidegger 75).
In actuality, logos meant more in ancient Greek than logic or reasoning, it meant "thought plus action" (Covino & Jolliffe 17). It appeals to patterns, conventions, and modes of reasoning that the audience finds convincing and persuasive (Covino & Jolliffe 17). Logos, pathos, and ethos are completely different, yet, they all correlate. Ethos moves an audience by proving the credibility of the rhetor; pathos stimulates the feelings of the audience and seeks change in their attitudes and actions; and logos, along with ethos and pathos, mobilizes the powers of reasoning (Covino & Jolliffe 17). A rhetor must consider all three means of persuasion if he is to convince the audience of the conclusion he wants them to believe or act upon. Before engaging in discourse, the rhetor must ask himself the following:
Logic, the main component of logos, is the study of the principles and methods of argumentation (World Book 381). These arguments consist of a set of statements that serve as premises, or statements of evidence, that conclusions can be drawn from (World Book 381). The key to evaluating arguments is distinguishing the valid from the invalid ones. The following is an example of a valid argument:
And here, an invalid argument:
Sometimes the correctness of an argument depends on its form, not the actual truth or falseness of the premises (World Book 381).
With deductive logic, the conclusion is a necessary consequence of the premises with rules pretaining to valid arguments (World Book 381).
With inductive logic, the conclusion is only more or less probable on the basis of the premises (World Book 381). Because of this, the grounds for belief, or the validity of the premises, are studied (World Book 381). The premises of inductive arguments are based on generalizations, analogies, or causal connections (World Book 381). Principles making assertions about all members of a class of objects are generalizations and an analogy compares two or more things which agree in some respects (World Book 381). But, causal connections correlate to cause and effect (World Book 381). For example: If a person gets restless as the temperature rises, he might conclude that heat makes him restless, making a causal connection.
Aristotle was the first philosopher to analyze the process whereby propositions can be logically inferred to be true from two other propositions being true, which he called a syllogism (World Book 628). A syllogism, as I mentioned earlier, is the most common type of deductive logic. Aristotle called it the "main instrument for reaching scientific conclusions" (World Book 381). The "All men are mortal..." argument from earlier is a perfect example of the syllogism. It must have three terms, whereby two negative premises yield no conclusion, and two positive premises yield a positive conclusion (World Book 381). Yet, from a positive and negative premise, only a negative conclusion can result (World Book 381). Plus, the term occuring in both premises must be modified by "all" or "none" at least once (World Book 381). For example:
And this would conclude that the term that occurs in the conclusion that's modified by "all" or "none," must be modified by "all" or "none" in the premises.
An meme is more a transaction of logos based on assumptions, assertions or observations, and claims (Covino & Jolliffe 20). Aristotle defined enthymeme as a "rhetorical syllogism" saying that "enthymeme is to rhetoric as syllogism is to logic" (Covino & Jolliffe 20). With enthymeme, he stated that rhetors argue logically by citing examples in which the success of the argument depends on the acceptance of the context (Covino & Jolliffe 20). The major difference of enthymeme from syllogism is that neither the premises nor the conclusions are provable (Covino & Jolliffe 20).
The tools of logos are not totally related to logic and reasoning. Pathos and ethos must coinside with logos for the audience to accept the rhetor's observations about the subject as valid and to believe the conclusion the rhetor wants them to.
The concept of logos has bred many different theories and opinions over the centuries. Feminist today actually think of logos as a term of exclusion since it has references to a male god (Covino & Jolliffe). Perhaps, these feelings are warranted because even back in ancient Greece the ancients considered women to be on a lower scale of being, thus incapable of reason (Covino & Jolliffe 65). Today it's almost inconceivable that kind of mentality ever existed. From Aristotle's pisteis to Gorgias's diabolical forces and Heraclitus's divine reasoning, the power of logos has been analyzed and argued over.
None of these philosophers or theories are wrong and none are entirely right either. However, persuading people logically with discourse existed long before the actual term "logos" did. One thing that is true that no philospher could argue with is that logos has provided a key building block to the way we all communicate with one another today.
