 For a more detailed account of the genesis of Principia Mathematica and Whitehead’s place in the philosophy of mathematics, cf. Smith 1953, Code 1985, Grattan-Guinness 2000 and 2002, Irvine 2009, Bostock 2010, Desmet 2010, N. Griffin et al. 2011, N. Griffin &amp; Linsky 2013.