Ludwig Wittgenstein wrote:
A tautology . . . says nothing. (Tractatus, 5,142)
He further clarified:
The logical product of a tautology and a proposition says the same thing as the proposition. This product, therefore, is identical with the proposition. (Tractatus, 4,465)
Basically, Wittgenstein is saying that if T is a tautology and p is any proposition, then “T & p” has exactly the same meaning as p. Put differently, since T says nothing, T doesn’t contribute to the meaning of the conjunction “T & p”.
Apparently, Stalin disagreed with this, as we can infer from his reaction to something that happened at the trial of Nikolai Bukharin.
Bukharin asserted the following tautology at the end of his trial, on March 13, 1938:
I assert that I think what I think, and that I don’t think what I don’t think.
[Quoted in J. Hellbeck, “With Hegel to Salvation: Bukharin’s Other Trial”, Representations 107 (2009), p. 56]
According to Wittgenstein’s view, since Bukharin’s assertion is a tautology, it says nothing, and hence there could be no reason to expunge it from the published record of the trial. After all, again according to Wittgenstein, a record without that tautology would have exactly the same content as the one containing it.
But Stalin thought otherwise. He arranged for the tautology to be removed from the official transcript, which was then presented to the public in a truncated form. Arguably Stalin did this because he suspected that Bukharin tried to use the tautology to send a veiled message that his confession of various crimes was not given voluntarily and should not be believed. And Stalin may well have been right!
BTW, an unedited version of Bukharin’s final statement, which included this “tautology” as well as some other previously expunged parts, was finally published (in Russian) 58 years after his trial and execution.