[Originally published as Logic Lessons: Arguing from Silence]
Arguments from silence, like other fallacies, have some clear-cut examples that are easily identifiable.
The basic form is that if someone does not answer a question or give a response, it is taken as confirmation that the other person is right. Unfortunately, I do not have screenshots of one of my favorite examples.
An atheist on Twitter was attacking me for something or other, and I had better things to do (such as watching television). When I came back to Twitter, I realized that I had lost a “debate.” The guy had been firing off questions and comments and, because he did not get responses from me, he declared victory for himself—I lost a debate that I did not know I had!
Here is another one. It was posted in a forum, and I found out that it was e-mailed to me from a spammer-stalker who knows that I have blocked him from my e-mail:
“Oh, and his total FAILURE to answer my question below* proves that Bob Sorensen is a liar, full stop. . . . *I am afraid that silence from Bob will be taken to indicate that he is unable to do this, and that he makes untruthful statements about opponents that he cannot subsequently defend – thus I would advise him against ignoring this challenge.”
As you can see, he added several manipulative conditions on the failure to respond.
One more, and it is a challenge because it is complicated:
Norman the Paranoid Troll (long-time readers, do you remember him?) is using a weird combination of argument from silence and the either/or fallacy. By deleting his posted comments, the site owner admits that followers of Jesus lie and kill. “If you do not agree, be honest and let them stand,” which has the either/or fallacy of “If you do not let these comments stand, you are not honest.”
Very manipulative and despicable. And yet, the spammer-stalker quoted above this screenshot makes Norman seem almost sane.
On a side note (and I think I’ve said this before), if someone is going to say, think, and write evil about you, there is nothing you can do to stop him. When the antagonist is non compos mentis, just laugh and move on unless it is actual libel.
As with other fallacies, the argument from silence can blend and overlap with other fallacies (as we just saw).
Also, like other fallacies, the argument from silence can actually be valid on occasion when used with other valid evidence and is not a fallacy in those instances.
In my examples, I did not feel like indulging the critics who were making the demands. If I had made a claim and was challenged but did not respond, the other party might be justified in being suspicious. (Refusal to accept clear evidence does not count.) But such a use of argument from silence as valid evidence is tricky.
Yet again like other fallacies, it can take different forms.
What I am going into now is not the argument from silence per se, but I think these are forms of it. To say something like, “There’s no point in reporting it to maintenance, they won’t do anything anyway” or, “I’m not going to read that creation science stuff, I know what they’re going to say” have some things in common with the argument from silence. (I think there may be a bit of the appeal to motive fallacy mixed in as well.)
To me, these are just excuses to avoid taking action or learning something. Plus, precognition and clairvoyance are not generally accepted in discussions of logic.
The adage applies, “Absence of evidence is not evidence of absence.” Be on guard against someone who tries to pull a fast one by using an argument from silence, since it is a way to bully people into doing things and can lead to nonsensical “victories.”
And, as always, be careful that you do not do this yourself in a casual or manipulative manner.
Here is a good article on the basics of the “argument from silence.”