According to Buddhism, mental states can be divided into two basic types: kusala and akusala. The former (kusala) is all that makes you feel clear-headed and calm. For example, imagine a child lying in the grass on a beautiful summer day and looking up at the clouds; it is content with itself and the world, just happy, and relaxed. This is ‘kusala’. When you feel kusala, you are at ease, happy and content.
The opposite of this is ‘akusala’, which is, in simple terms, everything which upsets you or causes you emotional stress. This of course includes fear, sadness, anger - but also listlessness and apathy. Why? Because when you are apathetic and listless, you probably don't feel happy, but depressed - and this is also a form of stress.
Self-Reflection: Lying in the grass on a beautiful summer day...can you think of other, similar 'kusala'-situations?
The reason why the concept of kusala and akusala is so important in Buddhism is that it is related to ethical and social questions. For example: do you think it likely that a person in a state of kusala – remember, that is the state where one is happily lying in the grass looking up at the clouds - robs a bank? Probably not. Crimes are usually committed in states of akusala. The ancient Indian king Ashoka, who ruled his country according to the principles of the Buddhist Dhamma, recognized this already around 250 BCE and introduced, among else, extensive resocialization measures for criminals.* Because, people who feel kusala are much less likely to break the law.
Conversely, you might have had the experience that it makes you feel kusala when you help others or perform a good deed. Usually, this makes not only the other person happy, but yourself as well. Therefore, according to Buddhist logic, kusala states of mind are directly linked to virtuous behavior (In German, the proverb "A clear conscience makes a gentle resting pillow", expresses a similar idea). The 'Eightfold Path' which Buddhists practice was designed to provide a framework for a virtuous way of life, to help increase ‘kusala’. Why is this important? Because being in a kusala state of mind not only makes life more pleasant, but you will be able to meditate much better when you feel calm and content.
Self-Reflection: Think back of one time when you did something for another person and recall how their happiness affected your own mood.
For this reason, the narrative, mental imagery, and soundscape of the guided meditations in the self-help program were designed with great care, to make you feel as kusala as possible; because this will enable you to work on your OCD much better. Read more about how the CWSL would explain OCD, and what you can do about it from a Buddhist perspective, in the next section OCD in terms of the CWSL.
*Harvey, P.: Introduction to Buddhism: Teachings, History and Practices. Cambridge University Press, Second Edition.