0

I am lecturing a class in which a student has asked for my slides in advance. (My main reason for not doing this is to avoid students passively reading the answers to questions that I put to them in class.)

The student writes

Please upload slides before lecture; we need to take notes on the slides. A good lecturer can always decorate branches with leaves and flowers, so don't worry if someone read slides before hand

Leaving aside the metaphor of "leaves and flowers", I read the statement in the second sentence as equivalent to

A good lecturer would make slides available in advance.

...with the tacit implication that a lecturer who does not make slides available in advance is a bad lecturer.

What logical fallacy or fallacies may be occurring here?

  • 2
    If you mean the fallacy (P ➡️Q) ➡️(~P ➡️~Q) , then you're after denying the antecedent. Otherwise, you might have a false dilemma (there might be more than one way to be a good lecturer). – Dan Bron Aug 6 '17 at 11:17
  • Of the responses thus far, this is the most succinct and compelling to me. Thank you @DanBron and other contributors. – David Lovell Aug 7 '17 at 8:26
1

The student forces a false dilemma (and false dichotomy) on you, as Dan Bron suggests. You feel you are in a dilemma: either you have to make slides available in advance, which you don't want to (it appears to me), or you might be viewed as a bad lecturer by the student who sent you the email. Luckily you are not in the dilemma because the student's reasoning is based on false dichotomy.

If you are a good lecturer, then you make slides available in advance.

=If you do not make slides available in advance, you are not a good lecturer.

=Either you make slides available in advance or you are not a good lecturer.

The student assumes that there are only two mutually exclusive options for you: making slides available in advance, and being a not-good (bad) lecturer. But a person can be a bad lecturer even if she makes slides available in advance, or a person can be a good lecturer despite making slides unavailable in advance. Some good lecturers do not have any slides at all!

This false dichotomy turns into false dilemma since neither option is palatable.

2

...with the tacit implication that a lecturer who does not make slides available in advance is a bad lecturer.

This is not a logical fallacy. It's just an opinionated assumption.

Based on the structure of the phrasing, you are possibly thinking of No True Scotsman. This is where you make an assertion like "no lecturer would..." which, when it is refuted with a counterexample, you move the goalposts with a vague refinement to "no good lecturer would..."

But I don't think that it applies in your case.

0

This is not a logical fallacy. In logic "If A, then B" is equivalent to the so called contraposition "If not B, then not A". Both statements are true (or false) under same conditions. You can only doubt that "If good lecturere, then slides are made available in advance" is a true statement. But that has nothing to do with logic.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.