Armour, Leslie.  "Logic and Experience in Whitehead's Metaphysics."  Process Studies 21, no. 4 (Winter 1992): 203-18.

Abstract

Whitehead believes that a conceptual scheme can be necessary and appropriate to the interpretation of experience, not merely a set of tautologies consistent with all experience.  I suggest that this doctrine can be explained and defended is suggested by Whitehead's account of "ideas".  Ideas have logical properties some of which are necessary, but also figure in experience, and so have properties which must be known empirically.  I argue that these notions suggest not only how necessity and experience "can" go together, but also clarify the relations between several of Whitehead's most important concepts.  [Abstract from The Philosopher's Index]