Topics are arranged alphabetically in the INDEX.

Sunday, April 7, 2013

Introduction to Logic: Fallacies

Logic is the study of reasoning and the process by which an argument can be determined to be logical, valid and sound. Logicians analyze arguments, premises, inferences, propositions, conditional statements, and symbolic forms.

Logic should not be confused with epistemology which explores theories of knowledge. Logic is concerned with how we reason.

Aristotle was one of the earliest philosophers to articulate principles of logic. His most famous works on Logic are: Categories; On Interpretation; Prior Analytics; Posterior Analytics; Topics; and Sophistical Refutations. Aristotle insisted that his students reason according to the Laws of Identity, Non-contradiction, and the Excluded Middle. He called these "first principles".

Other famous works on Logic include:

Francis Bacon: Novum Organum

Descartes: Discourse on Method

John Dewey: Reconstruction In Philosophy

John Stuart Mill: System of Logic

W.V. Quine, Mathematical Logic

Bertrand Russell: The Problems of Philosophy; The Principles of Mathematics

Gilbert Ryle: Dilemmas

Ludwig Wittgenstein: Philosophical Investigations

Rudolf Carnap, Introduction to Symbolic Logic and its Applications

Alonzo Church, Introduction to Mathematical Logic

M.R. Cohen and Ernest Nagel, An Introduction to Logic and Scientific Method

W.W. Fearnside and W.B. Holther, Fallacy -- The Counterfeit of Argument

As a branch of philosophy, logic has many subsets: modal logic, many-valued logic, modern logic, symbolic logic, formal and informal logic, deductive and inductive logic.

Our study of logic is designed to help the student identify fallacies. A fallacy is an invalid form of argument, and represents an instance of incorrect reasoning. There are numerous fallacies. Below is a list of common fallacies.

affirming the consequent

anthrocentric fallacy

appeal to authority

a priori fallacies

arguing from "is" to "ought"

argumentum ad baculinum

argumentum ad captandum

argumentum ad crumenam

argumentum ad hominem

argumentum ad ignorantiam

argumentum ad lazarum

argumentum ad misericordiam

argumentum ad populum

argumentum ad verecundiam (see "appeal to authority")

argumentum ex silentio

begging the question

circular reasoning


fallacy of false alternatives

fallacies of interrogation


gadarene swine fallacy

genetic fallacy

hasty generalization

if-then fallacies

ignoratio elenchi

invincible ignorance

naturalistic fallacy

non sequitur


performative contradiction

petitio principii (see "begging the question")

poisoning the wells

post hoc ergo propter hoc

red herring

straw man fallacy

tu quoque fallacy

undistributed middle

Fallacies generally can be avoided by following Charles Sanders Peirce's 3 rules of reason.

"Upon this first...rule of reason, that in order to learn you must desire to learn, and in so desiring not be satisfied with what you already incline to believe, there follows one corollary which itself deserves to be inscribed upon every wall of the city of philosophy: Do not block the way of inquiry."--Charles Sanders Peirce, 1896

Related reading: Dorothy Sayers' Lost Tools of Learning; A Pragmatic Approach to Knowledge; Student Graphics Illustrate Fallacies; Logic on the Lighter Side

No comments:

Post a Comment