The other four skandhas describe our psychological makeup. Sensation is what occurs when we come into contact with the environment, and it can be pleasant, unpleasant, or neutral. Perception is the awareness of that with which what we have interacted, including recognition, discrimination, and judgment. Volition is the decision or intention to respond to the interaction, whether by thought, speech, or action.

The fifth skandha—consciousness—is much more than the ‘consciousness’ that is usually defined in the West. In fact, the combination of sensation, perception, and volition make up ordinary discriminating consciousness, our thought process. The fifth skandha results when form, sensation, perception, and volition interact. It includes the consciousness we normally refer to as cognition, plus what we define as the self. It is the ‘I’ that creates meaning in what we experience and holds these mental processes together, preventing them from falling to pieces. The fifth skandha is the recipient and creator of karma, and continues from life to life. We can say that the fifth skandha is the conesquence of previous karma; and karma is that which results from the interaction of the first four skandhas with the karmic world-the result of our past actions. Therefore, the fifth skandha is our self-perpetuating mechanism. But consciousness without the other four skandhas could not produce karma. In fact if any one of the five skandhas is absent, then the entire process breaks down. All five skandhas are necessary for interaction.