Stanway, Ross.  "Whitehead on the Concept of 'Importance'."  Process Studies 21, no. 4 (Winter 1992): 239-45.

Abstract

The concept of 'importance' permeates Whitehead's thought.  Though derived from Whitehead's Categoreal Scheme, it is a generic concept which plays a fundamental role in the philosophy of organism.  It describes the intensity of feeling for, and the gradation of, the relevant characteristics a subject invokes in the process of its self-determination.  'Importance' involves, both for physical and conscious purposes, the subject's aim (purpose) and its self-objectification (valuation).  And, it does so by the pursuit of the ideal of unity in concrete modes of expression.  [Abstract from The Philosopher's Index]