These belong together

I believe that the following three quotations, from philosophers not unknown to each other, share something in common and should therefore be considered together:

The most savage controversies are those about matters as to which there is no good evidence either way.

Bertrand Russell (1872-1970)

Whereof one cannot speak, thereof one must be silent.

Ludwig Wittgenstein (1889-1951)

What we can't say we can't say, and we can't whistle it either.

Frank Ramsey (1903-1930)


To these may be added:

Whereof we cannot speak, thereof we must write children’s books.
Francis Spufford (b 1964) (From: The Child Books Built, 2002)