ABSTRACT
Perhaps the most useful yet simple metaphor for a healthy area of inquiry and application is that of a vital center and an expanding periphery. Why? In the absence of an expanding periphery, to illustrate, the danger is that the center’s validity cannot be validated by testing; nor is a growing and enthusiastic cohort of workers-in-the-vineyard probable in the absence of an expanding periphery. Hence, lacking an energetic periphery, even a valid core is likely to suffer, and perhaps stagnate. At an extreme, indeed, the core may in time collapse on itself. Or, in another form, if real testing of the core by extending the periphery does not occur, the core and its peripheries may drift apart, as it were, thereby impoverishing both.
