The present paper explores some of the characteristics and implication
s of the approach to scientific theories and theoretical concepts that
developed under the auspices of mediational S-O-R neobehaviorism duri
ng the middle of the present century. Of special interest is the evalu
ation of scientific theories and theoretical concepts, notably ''hypot
hetical constructs'' and ''intervening variables,'' in terms of realis
m, instrumentalism, and pragmatism The paper argues that many contempo
rary behavioral theorists who embrace the aforementioned approach ofte
n fail to understand the verbal processes by which scientific verbal b
ehavior develops. The result is an unfortunate confusion of epistemolo
gical principles that does not adequately distinguish among realism, i
nstrumentalism, and pragmatism.