There is not only one health, but there are as many healths as there are human beings. We must incorporate that in our attitude if we want to see the issues of health and illness in the right light. We must incorporate in our attitude that the human being is an individual being that every human being is different from the other, and that that which is salutary to the one is noxious and disease causing to the other, that it completely depends on his individual state.

Source: Rudolf Steiner – GA 57 – Where and How Does One Find the Spirit?: Lecture VIII: Issues of Health in the Light of Spiritual Science – Berlin, 14th January, 1909