Loosely speaking, congruence means genuineness. People are congruent when they are not trying to appear to be anything other than what they are. Congruence is the opposite of dissemblance. It is closely related to a number of other terms, some of which will concern us below: honesty, authenticity, transparency, immediacy, spontaneity; yet its meaning does not precisely coincide with any of these.
As a topic in psychotherapy, congruence is concerned with a person's attempts to achieve harmony in their way of being. We may speak here particularly of harmony between body and mind. Body, in this statement, refers primarily to behaviour, to all the movements and sensations which constitute our experience of our physical being. Mind refers to our sentiments, beliefs, emotions, thoughts and imagery. Sometimes we make this same distinction by talking about a person's "outer" and "inner" lives.
In practice, the line between body and mind cannot be drawn with precision. Nonetheless, the distinction is meaningful so long as we do not start to think that it is absolute. The more congruent we are, the less easy it becomes to distinguish one from the other. In Carl Rogers' terms, a person who is congruent becomes his (her) organism.
The term congruence is derived from a Latin word meaning harmony. I am incongruent when I am not in harmony with myself. A person who smiles (body) while actually feeling miserable (mind), is said to be incongruent. Much psychotherapy, personal growth and spiritual work revolves around the attempt to achieve self harmony, to eliminate incongruence. Incongruence is one of the most used sign-posts in psychotherapy. When the client manifests signs of incongruence, that is where the therapist is likely to focus attention.
While what has just been said is not untrue, there is a more revealing way to think about it. To say that therapy is about eliminating incongruence gives us a simple idea of the process. It tells us where to look, for instance. On the other hand, the human being is infinitely more complex than this simple prescription suggests. When we do focus upon some element of apparent incongruence in ourselves or in another person, what we find is that we are beginning to enter into an appreciation of some of that human complexity.