Even to this day it is easier than it ought to be for me to get a rise out of an American by telling him something about himself which is equally true about every human being on the face of the globe. He at once resents this as a disparagement and an assertion on my part that people in other parts of the globe are not like that, and are loftily superior to such weaknesses.
When you want to put something into your part that is not in the play, you must ask the author-or some other author-to lead up to the interpolation for you. Never forget that the effect of a line may depend not on its delivery, but on something said earlier in the play, either by somebody else or by yourself, and that if you change it, it may be necessary to change the whole first act as well.
Make it compulsory for a doctor using a brass plate to have inscribed on it, in addition to the letters indicating his qualifications, the words 'Remember that I too am mortal'.
What is really important in Man is the part of him that we do not understand. Of much of it we are not even conscious, just as we are not normally conscious of keeping up our circulation by our heart-pump, though if we neglect it we die.