This is a facility in Winston-Salem, North Carolina, where people were worried that the building might be structurally unsound from the weight of all that paper.
Grice did not give any example of disorder, which is understandable in that generally a disordered utterance will not convey anything but the fact that the speaker is mentally unsound.
I could imagine a man who, by living alone and at peace, came to regard the everyday world as not really existent, but a creation of his own fancy in unsound moments.
If the principle is unsound, we have no reason to expect the sun to rise to-morrow, to expect bread to be more nourishing than a stone, or to expect that if we throw ourselves off the roof we shall fall.