Many, arguably all, approaches within psychology are guided by assumptions. This is true whether practitioners and followers of these approaches are aware of these assumptions or not. Contextual Behavioral Science (CBS) tries to be clear about its assumptions and how they inform the work of ACT and RFT.
CBS is a form of ‘contextualism’ and as such is interested in the ongoing actions of the whole organism. It also view the actions of the organism within both its current and its historical context. In other words CBS is primarily interested in the act-in-context.
The precise variety of contextualism that CBS is based on is known as ‘functional contextualism’. The goal of functional contextualism is the prediction and influence of behaviour with precision, scope, and depth. ‘Prediction and influence’ are unified goals. CBS is not just interested in the prediction of behaviour but also influencing it. Accordingly CBS is less interested in variables which can not be directly manipulated. This is because even if a variable is related to a behaviour if that variable cannot be manipulated then the behaviour itself cannot be influenced. ‘Precision, scope and depth’ refer to a desire to be able to explain phenomena using as few concepts as possible (precision), while at the same time for those concepts to be able to explain as wide a range of phenomena of possible (scope) and for these concepts to be readily integrated with other levels of analysis (depth).
Finally, in the pursuit of this goal, CBS adheres to a ‘pragmatic truth criterion’. This means that it directs itself towards successful working rather than uncovering absolute truths. As such concepts used in CBS are valid if they prove to be successful at moving towards the goals of functional contextualism. This validity tends be assessed through the methods of science.