My contribution to this discussion reminds me of the ill-prepared Divinity student, who, asked in an examination to “Discuss the textual criticism of the Minor Prophets”, began, “Far be it from me to criticise these great and holy men, be it mine rather to give the list of the Kings of Judah and Israel”. For what I have to say has about the same degree of relevance to the topics discussed by the last two speakers as the student’s answer had to the question asked, and my remarks will, moreover, be more in the nature of a sermon than of a mathematical lecture. I hope, however, that they will serve as an illustration of the general subject under discussion, even though they may not bear very directly upon what has already been said.