Logical fallacies

Does objectivism have a concept similar to the concept of logical fallacies?

(I ask because objectivism views cognition as being done by the mind, so I guess it should focus more on _metnal_ mistakes (evasion being one) and not “logical” ones).

Well, Ayn Rand coined the fallacy of stolen concept. But yes, Objectivists would recognize other regular logical fallacies (ad hominem, post hoc ergo propter hoc, appeal to emotion, etc.).

Does objectivism have a concept similar to the concept of logical fallacies?

(I ask because objectivism views cognition as being done by the mind, so I guess it should focus more on _metnal_ mistakes (evasion being one) and not “logical” ones).

Logical mistakes are mental mistakes. Logic is simply the study of the rules of the processes of reason. When someone commits a logical fallacy, he is using the forms of reason to make an arbitrary assertion and is thus abandoning rationality.

The logical fallacies which Ayn Rand identified are all fallacies of concept formation. The reason she, rather than someone else, was able to identify these fallacies first is because she was the first to formulate a correct theory of concept formation. I have copied a list of these from the Objectivism Wiki below, all of which except for “Rewriting Reality” are examples of conceptual fallacies (“Rewriting Reality” is not so much a logical error as a pre-logical metaphysical error).

Following are examples of conceptual fallacies identified in the Objectivist theory of concept formation.

Floating Abstraction

Ayn Rand’s term for concepts detached from existents, concepts that a person takes over from other men without knowing what specific units the concepts denote

Frozen Abstraction

Substituting some one particular concrete for the wider abstract class to which it belongs

Invalid Concept

Package-Deal

Assuming that things often grouped together by tradition or culture must always be grouped that way

Reification of Zero

Regarding “nothing” as a thing, as a special, different kind of existent

Rewriting Reality

Attempting to alter the metaphysically given

Stolen Concept

Attempting to undermine the concept itself by attacking the hierarchial root(s) upon which it depend

Well, Ayn Rand coined the fallacy of stolen concept. But yes, Objectivists would recognize other regular logical fallacies (ad hominem, post hoc ergo propter hoc, appeal to emotion, etc.).

Strictly speaking, many of these are not themselves logical fallacies, in the colloquial sense of the term.

Strictly speaking, many of these are not themselves logical fallacies, in the colloquial sense of the term.

No, they are all logical fallacies. There are three kinds of logical fallacies: formal fallacies (having to do only with the form, not the content of the argument), such as affirming the consequent; informal fallacies (fallacies in the method of going from premises to conclusion), such as equivocation; and ignoratio elenchi (irrelevant conclusion, really a subtype of informal fallacies), such as argumentum ad hominem. Although some academics only consider formal fallacies “real” fallacies, that would not be the “colloquial” sense of the term.