Hurley, Patrick J.  "Russell, Poincare, and Whitehead's 'Relational Theory of Space'."  Process Studies 9, nos. 1-2 (Spring-Summer 1979): 14-21.

Abstract

Whitehead's 1914 essay, "The Relational Theory of Space", contains the first published presentation of the method of extensive abstraction.  The unique purpose given to the method in this essay suggests an early neo-Kantian influence on Whitehead by Poincaree, and sheds light on Whitehead's subsequent break with Russell in 1917.  In addition, certain passages in the essay anticipate the fallacy of misplaced concreteness and the ontological principle, and the analysis of causal relations in Section II provides the logical basis for the epochal theory of becoming in the philosophy of organism.  [Abstract from The Philosopher's Index]