In the fourth lecture of Human and Cosmic Thought Rudolf Steiner speaks of an inner Spiritual Astrology. This is a new inner Spirit astrology which looks inward to the human soul rather than outward to the external cosmos of the commonly known physical astrology. Spiritual Astrology is concerned with the possible varieties and configurations of world-views found in individual personalities. The twelve mental-zodiacal-signs stand in a relation to one another in a way that they form a mental copy of the Zodiac. As the sun passes through the Zodiac, so it is possible for the human soul to pass through a mental circle of 12 world-outlooks. A person may have a natural predisposition in which they are influenced by the world-outlook of Idealism. They may make this world-outlook a dominating factor in their inner life. According to Rudolf Steiner these influences are of much greater importance in the life of a person than the external horoscope and do not necessarily coincide with the "nativity" of the external horoscope of popular astrology
In our search for truth, individual personalities incline to let one or the other of these world-outlooks predominate. What convinces us of a certain point of view? Why can it be difficult to comprehend the viewpoint of another? Rather than disputing world-views, this new science is a way to peace through overcoming one-sidedness by understanding the truth-value of other views.
Diagram below of possible world- outlooks Human And Cosmic Thought. Lecture 3, P.50
The indications in Human and Cosmic Thought provide the basic principles for the development of Spiritual Astrology, but are rather sketchy with detail. The Philosophy of Freedom is filled with detail but takes confusing shifts in thought. It has been possible to align the two books through their common connections with the world-outlook diagram above. The development of thought in the Philosophy of Freedom follows this diagram which explains the shifting points of view in each chapter as being a movement through the twelve points of view. The lack of detail provided for the world-outlooks is now filled out with the detailed soul observations found in the Philosophy of Freedom. Now enough material is available to make the development of Spiritual Astrology a possibility. Many years of intensive study and human observation lie ahead before this new science of freedom takes its place along side of the other sciences.
And now try, from what has been explained, to enter into the task confronting Spiritual Science: the task of acting as peacemaker among the various world-outlooks. The way to peace is to realize that the world-outlooks conjointly, in their reciprocal action on one another, can be in a certain sense explained, but that they cannot lead into the inner nature of truth if they remain one-sided. One must experience in oneself the truth-value of the different world-outlooks, in order — if one may say so — to be in agreement with truth.
Rudolf Steiner, Human and Cosmic Thought P. 54