Informal fallacies are the ones you and I run across in everyday life, like the ad hominem, false appeal to authority (there IS a correct time to appeal to authority), and so forth.
Formal ones are like the old fallacy of the undistributed middle. Most formal fallacies, like it, relate to the good old Aristotelian syllogism.
What brings this up, other than me doing more philosophy-related blogging here?
A discussion on Facebook. Another person said that the gambler's fallacy, because it involved probability and statistics, was a scientific issue, not a philosophical one. I mentioned, in brief, the material above, and said that fallacious reasoning can involve different tools or material, but the actual fallaciousness was at bottom line, and thus, the gambler's fallacy like others was ultimately a philosophical issue.
I was eventually unfriended, even though I was polite about it. Had I been more direct, I would have said that she, in a small way, was doing something akin to Sam Harris, and a few other Gnu Atheists, in practicing scientism, which would have made her blood boil, probably. But, I believe that was the case. I did mention that I was a knight errant of philosopher Massimo Pigliucci in defending philosophy against such encroachments.
Or, to put it literarily?
Mark Twain mentioned "lies, damned lies and statistics," not "lies, damned lies and philosophy," thereby indirectly getting at what I was saying. Misuse of statistics is the particular tool used to commit fallacious reasoning in the gambler's fallacy. Per Wiki's list of informal fallacies, misuse of history can contribute to at least one of them.
I will concede the point that a lot of people misunderstand statistics. But, they don't misunderstand, or misuse, in a way that would always be fallacious. They can misunderstand false positives and false negatives, and not commit the gambler's fallacy. Even if we do invent a new category of fallacy, fallacious reasoning in general, at least to me, implies deliberation, or logical malice aforethought. And, I don't see that happening in a lot of the misuse of statistics.
I know that this is something near and dear to movement skepticism; that's another reason I understand some of her upset. On the other hand, I've said before that scientific "movement" skeptics need more immersion in philosophy, too.
Skeptic's Dictionary creator Robert Carroll indirectly weighs in on this in his latest email newsletter:
My educational background is in philosophy, where 'skepticism' has little to do with people like Dean Radin, John Edward, or Sylvia Browne. Until I read an article by Douglas Hofstadter in Scientific American in February 1982 entitled "World Views in Collision: the Skeptical Inquirer vs. The National Enquirer," I had only a passing interest in the kinds of things that are featured in Skeptic, Skeptical Inquirer, and The Skeptic's Dictionary. When I thought of skepticism, I thought of Pyhrro, the Academic skeptics, Sextus Empiricus, or David Hume's "mitigated skepticism." Skepticism, to me and others in philosophy, is an epistemological position, a set of tropes or methodological devices intended to cast doubt on any proposition put forth. The most radical skeptical position was presented by Gorgias: nothing exists or if something exists it cannot be known or if something does exist and can be known it cannot be communicated. Ancient philosophical forms of skepticism denied the possibility of certain knowledge. Academic skepticism advised seeking the best probabilities. By the time Hume proffered his "mitigated skepticism," philosophers known as empiricists had recognized that the idea of "objective knowledge" was absurd: all we know of "reality" emerges from the interaction of our minds with whatever exists independently of our minds in the external world and with the inferences we draw from that interaction.I, too, ultimately approach skepticism this way: "an epistemological position," but mitigated in a sense similar to Hume.
And, this is another reason I'm not part of the "tribe" of movement skeptics or Skeptics™any more than I am the tribe of Gnu Atheists. Beyond the issue of tribalism, too many members of each group, from what I see, don't have as much immersion in philosophy as they could stand. Also per Carroll, some of them may need to broaden their critical thinking base.
Also, this is why social media isn't always so good for we Lincolnesque cogitating reasoners. The part where I recognize this other person's concern over non-fallacious misuse of statistics, and its impingement on her professional background, came 36 hours after the defriend. Thus, while the likes of Facebook is real in a sense, it does show the problems with the Internet continuing to accelerate modern society.
That's not meant as hand-to-forehead martyrdom or anything else, the Lincolnesque statement. It's just that, ideally, slower cogitation is how I like to think. Per the "36 hours," I started working on this blog post a full week before I had it scheduled to publish. I often get less snarky, or at least make a more conscious choice about it, with more thinking time.