Skip to main content

Verified by Psychology Today


Acceptance and Commitment Therapy: A Philosophical View

Different modes of therapy can depend on different theories of the mind.

Key points

  • Two widely used forms of therapy have distinctive views of motivation and the mind.
  • CBT posits that common mental disorders result from faulty patterns of thinking and aims to change beliefs.
  • ACT acknowledges existing mental states but focuses attention on changing intentions.

There are two forms of behavior-oriented therapy that are widely practiced and adopted today. One is cognitive-behavioral therapy (CBT), a well-studied intervention for depression, anxiety, and a host of other psychological concerns. One of the core ideas of CBT is that conditions such as depression are due in part to defective patterns of thinking, and a core aim of therapy is to lead the client to more adaptive beliefs.

Anna Urlapova/Pexels
Source: Anna Urlapova/Pexels

There is another form of behavior-oriented therapy, however—acceptance and commitment therapy, or ACT. (Somewhat confusingly for those new to the subject, this is pronounced not as an acronym but as a single word: act.). Developed by the psychologist Steven C. Hayes, ACT is often presented as an alternative to CBT but can also be seen as an update or development of it. However it's categorized, there are disanalogies between ACT and CBT that are of philosophical, as well as clinical, interest.

Where inducing or inviting cognitive change is central to CBT, ACT is not as focused on revising beliefs. Instead, a crucial step in ACT is acknowledging one's psychology to be exactly as it is—and not avoiding it through mental mechanisms (denial, displacement) or extra-mental ones (substance use, thrill-seeking). The acknowledgment does not necessarily mean endorsing beliefs: ACT places great weight on getting a measure of distance from our mental states, or "defusion." But it does mean that, in contrast to traditional CBT, changing the beliefs that one has is not at the core of the therapeutic process.

Where change takes place in ACT is not in what one believes but in what one does. ACT places great emphasis on the clear articulation of one's values and in acting in accord with those values, whatever one's beliefs. Consider someone who believes they are unathletic but places great value on self-expression through physical activity. An ACT strategy might be for this person to find some way of expressing themselves physically (for instance, by enrolling in a dance class) rather than attempting to change the belief that appears to stand in the way. It is always possible, and often advisable, to act contrary to our fixed beliefs in pursuit of what matters to us.

Understanding the distinctive aspects of ACT in a broader philosophical context highlights the differences between two views of motivation and the mind.

In a traditional and influential view, often called the Humean view after its great advocate, the philosopher David Hume, the human mind basically has two kinds of states—beliefs, which represent how the agent takes the world to be, and desires, which represent how the agent prefers to world to be. Human action is typically simply the output of belief and desire: an agent wants ice cream, believes that there is ice cream at the supermarket, and so goes to the supermarket.

One objection to this view is that it leaves out states like intention, decision, and choice; it leaves out, for lack of a better word, the will. My intentions and choices are not quite beliefs about the world, but they are not quite mere desires either. They appear to be a third kind of state, irreducible to belief and desire. This kind of observation has led many contemporary philosophers, such as Michael Bratman and Richard Holton, to instead endorse a non-Humean view of human psychology.

In a Humean view, there are limited options if one is aiming to modify someone's psychology, and so their behavior. Most Humeans think, not implausibly, that desires cannot be changed by reason: one cannot talk someone out of wanting ice cream. Therefore, since an agent's psychology is nothing but their desires and beliefs, psychological change, if it is rational, must go via a change in beliefs.

A non-Humean view, offers additional possibilities. There may be psychological change that does not necessarily involve any change in belief or desire. Instead, an agent may change their intentions.

Clinical practice seems to provide many cases of such change. Consider someone with a substance use disorder who decides, one day, to refrain from using their substance of choice and continues to maintain that decision for months and years afterward. This does not necessarily seem to involve any change in what the agent believes about the substance (they have long believed it to be harmful) or even any change in the agent's desire to use the substance (which may persist for a long time afterward). The change seems to lie rather in what the agent chooses to do, and how they resolve to live.

Returning from philosophical psychology to the question of therapeutic practice, this contrast between two views of the mind maps nicely onto the divide between behavior-oriented therapies that focus on belief change, notably CBT, and those that direct their attention elsewhere, notably ACT. Indeed, if one approaches matters from a Humean point of view, it is difficult to see how one could rationally induce real change by anything other than by changing an agent's beliefs—namely, by something like CBT. But, for a non-Humean, new possibilities open up.

I do not want to emphasize too close a connection between philosophical views and therapeutic ones. For one thing, advocates of ACT have in fact claimed to have found their philosophical motivation elsewhere, in a kind of pragmatism that they dub "functional contextualism." But I do want to suggest that presuppositions about the structure of mind can induce limited views about what can, and cannot, be accomplished in therapy, and that discarding these presuppositions may yield new views of therapy and its possibilities.

More from John T. Maier
More from Psychology Today
More from John T. Maier
More from Psychology Today