1) The philosophy of the science of human behavior. It is the position that we can study behaviour scientifically and that we do so by finding the variables of which it is a function. Modern behaviourism is further separated into methodological behaviorism, which holds that the behaviour we can study is only that which can be measured by two independent observers (thus excluding all inner behavior) , and radical behaviorism, which includes inner behaviours such as "thoughts" and "dreams" as valid behaviour to investigate. B.F. Skinner is the leading spokesman for radical behaviorism, which is the position taken in this book.

2) The scientific philosophy of behaviour analysis.