PRESENT-DAY philosophy suffers from an unhealthy faith in Kant.  This essay is intended to be a contribution toward overcoming this. It would be wrong to belittle this man's lasting contributions toward the development of German philosophy and science. But the time has come to recognize that the foundation for a truly satisfying view of the world and of life can be laid only by adopting a position which contrasts strongly with Kant's. What did he achieve? He showed that the foundation of things lying beyond the world of our senses and our reason, and which his predecessors sought to find by means of stereotyped concepts, is inaccessible to our faculty of knowledge. From this he concluded that our scientific efforts must be limited to what is within reach of experience, and that we cannot attain knowledge of the supersensible foundation, of the “thing-in-itself.” But suppose the “thing-in-itself” and a transcendental ultimate foundation of things are nothing but illusions! It is easy to see that this is the case. It is an instinctive urge, inseparable from human nature, to search for the fundamental nature of things and their ultimate principles. This is the basis of all scientific activity.
There is, however, not the slightest reason for seeking the foundation of things outside the given physical and spiritual world, as long as a comprehensive investigation of this world does not lead to the discovery of elements within it that clearly point to an influence coming from beyond it.
The aim of this essay is to show that everything necessary to explain and account for the world is within the reach of our thinking. The assumption that there are principles which belong to our world, but lying outside it, is revealed as the prejudice of an out-dated philosophy living in vain and illusory dogmas. Kant himself would have come to this conclusion had he really investigated the powers inherent in our thinking. Instead of this, he shows in the most complicated way that we cannot reach the ultimate principles existing beyond our direct experience, because of the way our faculty of knowledge functions. There is, however, no reason for transferring these principles into another world. Kant did indeed refute “dogmatic” philosophy, but he put nothing in its place. This is why Kant was opposed by the German philosophy which followed. Fichte,  Schelling  and Hegel  did not worry in the least about the limits to cognition erected by Kant, but sought the ultimate principles within the world accessible to human reason. Even Schopenhauer, though he maintained that the conclusions of Kant's criticism of reason were eternal and irrefutable truths, found himself compelled to search for the ultimate cause along paths very different from those of Kant. The mistake of these thinkers was that they sought knowledge of the highest truths without having first laid a foundation by investigating the nature of knowledge itself. This is why the imposing edifice of thought erected by Fichte, Schelling and Hegel stands there, so to speak, without foundations. This had a bad effect on the direction taken by the thought of these philosophers. Because they did not understand the significance of the sphere of pure ideas and its relationship to the realm of sense-perceptions, they added mistake to mistake, one-sidedness to one-sidedness. It is no wonder that their all too daring systems could not withstand the fierce opposition of an epoch so ill-disposed toward philosophy; consequently, along with the errors much of real value in their thought was mercilessly swept away.
The aim of the following inquiry is to remedy the lack described above. Unlike Kant, the purpose here is not to show what our faculty of knowledge cannot do, but rather to show what it is really able to achieve.
The outcome of what follows is that truth is not, as is usually assumed, an ideal reflection of something real, but is a product of the human spirit, created by an activity which is free; this product would exist nowhere if we did not create it ourselves. The object of knowledge is not to repeat in conceptual form something which already exists, but rather to create a completely new sphere, which when combined with the world given to our senses constitutes complete reality. Thus man's highest activity, his spiritual creativeness, is an organic part of the universal world-process. The world-process should not be considered a complete, enclosed totality without this activity. Man is not a passive onlooker in relation to evolution, merely repeating in mental pictures cosmic events taking place without his participation; he is the active co-creator of the world-process, and cognition is the most perfect link in the organism of the universe.
This insight has the most significant consequences for the laws that underlie our deeds, that is, our moral ideals; these, too, are to be considered not as copies of something existing outside us, but as being present solely within us. This also means rejecting the “categorical imperative,” an external power whose commandments we have to accept as moral laws, comparable to a voice from the Beyond that tells us what to do or leave undone. Our moral ideals are our own free creations. We have to fulfill only what we ourselves lay down as our standard of conduct. Thus the insight that truth is the outcome of a free deed also establishes a philosophy of morality, the foundation of which is the completely free personality.
This, of course, is valid only when our power of thinking penetrates — with complete insight — into the motivating impulses of our deeds. As long as we are not clear about the reasons — either natural or conceptual — for our conduct, we shall experience our motives as something compelling us from outside, even though someone on a higher level of spiritual development could recognize the extent to which our motives originated within our own individuality. Every time we succeed in penetrating a motive with clear understanding, we win a victory in the realm of freedom.
The reader will come to see how this view — especially in its epistemological aspects — is related to that of the most significant philosophical work of our time, the world-view of Eduard von Hartmann. 
Clearly, the ultimate goal of all knowledge is to enhance the value of human existence. He who does not consider this to be his ultimate goal, only works as he learned from those who taught him; he “investigates” because that happens to be what he has learned to do. He can never be called “an independent thinker.”
The true value of learning lies in the philosophical demonstration of the significance of its results for humanity. It is my aim to contribute to this. But perhaps modern science does not ask for justification! If so, two things are certain. first, that I shall have written a superfluous work; second, that modern scholars are striving in vain, and do not know their own aims.
In concluding this preface, I cannot omit a personal remark. Until now, I have always presented my philosophical views in connection with Goethe's world-view. I was first introduced to this by my revered teacher, Karl Julius Schroer  who, in my view, reached such heights as a scholar of Goethe's work because he always looked beyond the particular to the Idea.
In this work, however, I hope to have shown that the edifice of my thought is a whole that rests upon its own foundation, and need not be derived from Goethe's world-view. My thoughts, as here set forth, and as they will be further amplified in The Philosophy of Spiritual Activity, have been developed over many years. And it is with a feeling of deep gratitude that I here acknowledge how the friendliness of the Specht family in Vienna, while I was engaged in the education of their children,  provided me with an ideal environment for developing these ideas; to this should be added that I owe the final shape of many thoughts now to be found in my “Philosophy of Spiritual Activity” to the stimulating talks with my deeply appreciated friend, Rosa Mayreder  in Vienna; her own literary works, which spring from a sensitive, noble, artistic nature, presumably will soon be published.
Written in Vienna in the beginning of December 1891.
Dr. Rudolf Steiner