A mystic, poet, psychotherapist and publisher, he was a magnetic and controversial genius who provoked both lasting affection and deep antipathy, sometimes simultaneously.
He held that Sufism has three aspects: it is non-definitive, inclusive, and experiential -
Two collections of his lectures have been published: "Old thinking, new thinking: The Sufi prism and "Modern soefisme : over creatieve verandering en spirituele groei (Modern Sufism: on creative change and spiritual growth).
As a psychotherapist and early promoter of Neuro Linguistic Programming he was the main motivating force behind the creation of the Association for Neuro Linguistic Programming and the inspiration for the Neuro Linguistic Psychotherapy and Counselling Association.
"Sufism is a call, a cry to awaken, to the minds who are ready, to the human beings who have slept enough, but to those who still want to sleep, it is merely a lullaby along in their dream."
"My mind is limited. But my heart is not, I hope."
"... minds are not made to agree, but to express beauty ..."
"Sufism, then, is an attempt to bring us to the point at which we have the freedom, the courage, to look at things as a baby does, without foreknowledge"
"Many people are interested in meditation, but not so many are interested in computer programming. Yet computer programming is so similar that you could call it meditation."