33 I have spent the labour of two nights in dictating for you this treatise; and in doing so I have felt a grief as deep as your own. I say in 'dictating' for I have not been able to write it myself. As often as I have taken up my pen and have tried to fulfil my promise; my fingers have stiffened, my hand has fallen, and my power over it has vanished. The rudeness of the diction, devoid as it is of all elegance or charm, bears witness to the feeling of the writer.
Source: Letters (New Advent)