Continuing my series on logical fallacies, we come now to "non causa pro causa," or false cause.
Post hoc ergo propter hoc
"After this, therefore because of this." The argument attempts to attribute cause to the thing that happened before. (See, also, "correlation is not causation.") This is essentially where superstitions come from.
Example: "I've created a million jobs since I'm president," a politician claimed after six months in office. It turns out, that job growth was consistent with (but slightly lower than) job growth under the previous office holder going back six years, making it improbable that the politician had anything to do with the jobs.
Another example: "Since taking office I have been very strict on Commercial Aviation. Good news - it was just reported that there were Zero deaths in 2017, the best and safest year on record!" By that criterion, so were 2016, 2015, 2014, 2013, 2012, 2011, and 2010. In fact, regulations governing air-transport flying were tightened in 2013.
Reductio ad absurdum
A "reduction to the absurd" tries to show that an assumption is false if a contradiction can be drawn from it. Usually, however, one or more of the premises of the argument is false.
The classic example uses a pair of syllogisms:
P1: A statesman acts in the public interest.
P2: Senator Jones is a statesman.
C1: Therefore, Senator Jones acts in the public interest. (Valid but possibly untrue.)
P3: Statesmen do not campaign for public office.
P4: Senator Jones campaigns for public office.
C2: Therefore, Senator Jones is not a statesman. (Valid but probably untrue given C1.)
The problem is probably premise #3. It's certainly the weakest link in the chain.
Another example: "America is the greatest country on earth, and we're making America great again." But...
Final example: "If your orders are always followed, then why was Private Santiago's life in danger?"
I'll leave it as an exercise to the reader to tease out the syllogisms of the last two examples.
Next time, a lot of questions, and squirrels.