Cannot one say what is true?

Stanley Cavell, The Claim of Reason, pp. 205–206:

“[…] Are you suggesting that one cannot sometimes say what is true?” What I am suggesting is that “Because it is true” is not a reason or basis for saying something; and I am suggesting that there must, in grammar, be reasons for what you say, or be a point in your saying of something, if what you say is to be comprehensible. We can understand what the words mean apart from understanding why you say them; but apart from understanding the point of you saying them we cannot understand what you mean.