"errors of non causae and ignoratio elenchi"
by cm

Fallacia non causae ut causae (fallacy of cause that is not cause) is a Latin phrase coined by Arthur Schopenhauer to describe the case where a conclusion that may be correct is drawn from an invalid argument or false reasons.  He uses it twice in The Art of Being Right (translated into English in 1896, just before the publication of Dracula):

Strategem XIV

This, which is an impudent trick, is played as follows: When your opponent has answered several of your questions without the answers turning out favourable to the conclusion at which you are aiming, advance the desired conclusion, - although it does not in the least follow, - as though it had been proved, and proclaim it in a tone of triumph. If your opponent is shy or stupid, and you yourself possess a great deal of impudence and a good voice, the trick may easily succeed. It is akin to the fallacy non causae ut causae.

Stratagem XX

When you have elicited all your premises, and your opponent has admitted them, you must refrain from asking him for the conclusion, but draw it at once for yourself; nay, even though one or other of the premises should be lacking, you may take it as though it too had been admitted, and draw the conclusion. This trick is an application of the fallacy non causae ut causae.


Ignoratio elenchi is a different kind of logical fallacy, where an argument is presented that is irrelevant to the question.  The argument may be valid, but it can only serve as a distraction to the point at issue.  Some speakers use such arguments deliberately.  The fallacy is said to have been identified by Aristotle.