First order perceptions - intensity

One perceives that something is there or that something is there which differs from what had been there. One is not normally conscious of these perceptions, despite the fact that they are the only direct contact with the outside world. These are intensity of feeling, for example, as of the buttocks on a chair, although one is only conscious of this feeling when the chair becomes uncomfortable and one registers the discomfort. All one feels is the energy of the signal or disturbance. First order perceptions do not register cause.

The first of ten orders in the perceptual system described by William Glasser.