(About ten short paragraphs, Revision One copyleft 5-21-2016 Peter Voluntaryistic Walker.)
Introduction: “Formal logics were developed in ancient times in China, India, and Greece. Greek methods, particularly Aristotelian logic (or term logic) as found in the Organon, found wide application and acceptance in science and mathematics for millennia” (http://en.wikipedia.org/wiki/History_of_logic). The Three Laws of Thought credited to Aristotle are the Laws of Identity, Non-Contradiction, and Excluded Middle. There’s much more to logic, but this set of three will do for starters.
1. The Law of Identity says a thing can only be itself.
1.a. For instance Shakespeare said a rose is a rose by any other name, and the same is true of a human being. An example violation is when people dehumanize each other, a textbook case being when Hitler dehumanized anyone he tagged “Jew” as being less than human.
1.b. All namecalling dehumanizes and is filler, meaning a replacement for content in an argument (argument in the context of making a case for or against something being true). Rudeness in general is also a form of namecalling because it’s a practice of treating humans as less than human.
2. The Law of Non-contradiction says everything has an opposite and a thing cannot be its opposite.
2.a. For instance some people argue against property rights while simultaneously using parts of their body as they see fit in order to communicate their message; thus refuting the existence of the very thing they’re doing. These are self-defeating arguments.
2.b. Claiming a knowledge exists when it doesn’t is also self contradicting. An example is people stating as fact they know what you think, understand, like, etc., when it’s impossible for anyone but you to know without sensors wired directly into your brain. They can can calculate probabilities based on your observable behavior, but there’s a large gap (aka does not follow, aka non sequitur error) between brain and outward behavior. For instance you may understand something and simply choose not to let on that you do.
3. The Law of the Excluded Middle says an argument can’t be true and false at the same time. “Either I will call my mother tomorrow, or I won’t call my mother tomorrow. One or the other of these statements about the future must be true. The principle that either a given statement or its denial is true is called the ‘Law of Excluded Middle.'” (David Hunt)
3.a. This law primarily addresses the semantics of accurately stating a problem or proposition. For instance, if an agreement has good and bad parts, it’s not a 100% good or bad agreement; to accurately describe it, it has two or more parts needing to each be understood separately from the other part(s). Thus I also call the excluded middle *conflation*, similar to what Ayn Rand called The Package Deal. It’s a critical law of logic because, whether intentionally or not, semantics often mislead.
3.b. Another conflation error is to conflate the already unconflated. For instance the non-aggression principal (NAP) says it’s immoral to initiate coercion. Many say this is a too simplistic “truncated argument” because it allegedly ignores things such as the alleged necessity of central planning or the alleged social contract. But according to The Law of Identity, adding such things would make it no longer the NAP. In such cases the avoided NAP core proposition is whether or not initiating coercion is moral — a complex argument involving definitions and interpretations of coercion, morality, initiation, and complex circumstances such as lifeboat scenarios and raising children. Therefore the NAP isn’t over simplified or truncated; rather it’s either a valid or invalid premise to be argued on its own merits. If it’s accepted as valid, then issues such as central planning and social contracts can be measured against it. If the NAP is invalid, obviously it’s irrelevant; but simply refusing to consider it is a non sequitur.
3.c. An equally common conflation error is goldplating; a textbook example being contractors for the USA Department of Defense writing specifications for hammers and toilet seats that made perfectly usable generic items unacceptable. Doing so provided the very same contractors with opportunities to sell hammers and toilet seats meeting their own specifications at multiple times the profit of generic items. Goldplating applies to present mainstream culture portrayals of critical thinking; that is, mainstream culture presents the tools of critical thinking such as logic as too complex for anyone to understand other than the spokespersons for the ruling classes, aka presstitutes and establishment-approved pseudo intellectuals.
I’ll write more mini-essays about logic and add the links here.