How have courts interpreted a plea of non est factum?

In Carlisle and Cumberland Banking Company v. Bragg, [1911] 1 K.B. 489, a case dealing with a plea of non est factum, Buckley, L.J., at pp. 495-496 stated: “The true way of ascertaining whether a deed is a man’s deed is, I conceive, to see whether he attached his signature with the intention that that which preceded his signature should be taken to be his act and deed. It is not necessarily essential that he should know what the document contains: he may have been content to make it his act and deed, whatever it contained; he may have relied on the person who brought it to him, as in a case where a man’s solicitor brings him a document, saying, ‘this is a conveyance of your property,’ or ‘this is your lease,’ and he does not inquire what covenants it contains, or what the rent reserved is, or what other material provisions in it are, but signs it as his act and deed, intending to execute that instrument, careless of its contents, in the sense that he is content to be bound by them whatsoever they are.”