The core principles of Person Centered Therapy like non-interference, natural healing, self-awareness and being true to oneself are valued in many cultures through history. Carl Rogers noticed similarities with Daoist thought later in his career.

Carl Rogers
He published a few propositions about human nature that were a bit like the beginnings of a theory of personality and put them into a wider context with observations on the nature of life and living beings. Later he described the well functioning person and suggested some basic principles to use to achieve that.

He developed Client Centered Therapy during the 1940's. This became ground breaking in the 50's and early 60's under the revised name Person Centered Therapy.

As an educator he applied the principles in student centered learning and later to society and politics..

Non Directive Psychotherapy has been used as an alternative name but the very presence of a therapist provides direction so this term has been somewhat confusing and controversial.

So where did this come from? My experience of the trance-like person centered session is of a free association that begins with a preoccupation or feeling of discomfort about something.

Free association was the first method of psychoanalysis. Freud abandoned hypnosis and adopted free association in 1892 as a clinical technique to recover and understand important memories while conscious. The critical mind does not intervene to censor spontaneous thoughts. Intellectual censorship is temporarily suspended and one freely follows a train of thought.

6 years later from 1898 Freud left free association aside to focus more on the analysis of the internal mental conflicts which kept these memories inaccessible (hypnosis didn't really work for Freud and neither did free association – memories remained stubbornly buried).

This new Psychoanalysis used reason and the influence of an analyst's authority to interpret to patients the origins of their feelings, thoughts and behaviour. These insights were to free them from unproductive or distressing habits and preoccupations.

Rogers got free association to work by staying out of the way and allowing awareness to emerge rather than explaining or debating.

current practice
Most of his terminology and ideas have entered our language and are taken for granted even though it is no longer widely practised in its purest form (or at least there are few of us who call ourselves Person Centered Therapists). However Rogers is at the time of writing this the therapist most recognised by professional psychotherapists.

The principles he found words for have become widely accepted and have found their way into many theories and practices. They are still widely considered to be basic principles of therapy.

Many therapies including some body work, emotional, play, art and music therapies now specify a person centered approach.