As if in response to my inner thoughts...
Life is a very complicated business if you want to do it well. This is because anything of any importance is always a many-sided affair and none of its different aspects may be neglected, while at the same time, in order to do the whole job well, the different concerns have to be separated as ruthlessly as possible.
His letter to Dr. Leslie Lamport is
here (in bits and pieces), in which he provides a case for why termination of a program can be ignored (in his opinion) for the time being.