Rudolf Steiner said the following about this essay in Chapter XXXI of his autobiography, The Course of My Life:
I experienced this “standing before the portal” of the spiritual world even more significantly in an essay I had to write for another volume. This volume was not devoted to the work of one century, but rather was a collection of essays meant to characterize the various realms of knowledge and life insofar as human “egoism” is a driving force in the development of these realms. Arthur Dix published this volume. It was entitled Egoism and was totally consistent with that period — the turn of the nineteenth into the twentieth century.
The impulses of intellectualism, which since the fifteenth century have affected every realm of life, are rooted in the “individual life of the soul” if they truly manifest their essential nature. If someone expresses himself intellectually out of the social life, this is then not a true intellectual manifestation but only an imitation.
One of the reasons why the call for social feeling in our age has rung out so strongly is that in intellectuality this feeling is not experienced in its original inwardness. Even in such matters, mankind's greatest craving is for what it does not have.
The task given me in this volume was to portray “egoism in philosophy.” My essay now bears this title only because the overall title of the book demanded it. My title should actually be: “Individualism in Philosophy.” I sought, in a very brief form, to give an overview of western philosophy since Thales, and to show the development of this philosophy toward an individual experience of the world in ideal pictures (in Ideenbildern); I sought to do this in the same way I attempted it in my Philosophy of Spiritual Activity for man's cognitive and moral life.
With this essay I again stand before the “portal of the spiritual world.” Within the human individuality the ideal pictures are indicated that reveal the content of the world. They arise and wait to be experienced, so that in them the soul can then advance into the spiritual world. I stopped at this point in my presentation. An inner world stands there that shows how far mere thinking comes in grasping the world.
One can see from this that, before devoting myself publicly to the anthroposophical presentation of the spiritual world, I portrayed the pre-anthroposophical life of the soul from the most varied points of view. There is no contradiction between them and my stand on anthroposophy. For the picture of the world that arises is not refuted by anthroposophy; it is broadened and carried further by it.
If someone begins as a mystic to present the spiritual world, then everyone is fully justified in saying: You are speaking of your personal experiences. What you are portraying is subjective. To tread this kind of a spiritual path did not arise for me out of the spiritual world as my task.
My task consisted in creating a foundation for anthroposophy just as objective as scientific thinking is when it does not stop short at recording sense-perceptible facts but rather presses on to comprehensive concepts. What I presented scientifically philosophically, what I presented natural-scientifically in connection with Goethe's ideas, this one could discuss. One could consider it to be more or less correct or incorrect; it did, however, strive to have the character of something objectively scientific in the fullest sense.
And out of this activity of knowing, free of all emotional mystical elements, I then drew forth the experience of the spiritual world. One can see how, in my books Mysticism at the Dawn of the New Age and Christianity as Mystical Fact, the concept of mysticism is led in the direction of this objective activity of knowing. And look especially at the way my Theosophy is presented. With every step that is taken in this book, spiritual vision stands there in the background. Nothing is said that does not stem from this spiritual vision. But as the steps are being taken, it is first of all, at the beginning of the book, natural-scientific ideas in which this vision cloaks itself; then this vision, in ascending into the higher worlds, must become ever more active in freely forming pictures of the spiritual world. But these pictures grow from what is natural-scientific like the blossom of a plant grows from its stem and leaves. Just as the plant is not beheld in its completeness if one views only its stem and leaves, so nature is not experienced in its completeness if one does not ascend from what is sense-perceptible to the spirit.