What is here called monism, this unitary explanation of the world, derives from human experience  the principles it uses for explaining the world. The source of activity also is sought within the world to be observed, that is, in human nature accessible to self-knowledge, more particularly in moral imagination. Monism refuses to seek the origin of the world accessible to perceiving and thinking, outside of that world, by means of abstract conclusions. For monism, the unity that thinking observation — which can be experienced — brings to the manifold plurality of perceptions is, at the same time, just what the human need for knowledge demands, and by means of which entry into physical and spiritual realms is sought. One looking for another unity behind the one sought by thinking observation, thereby shows only that he does not recognize the agreement between what is found by thinking and what the urge for knowledge demands. The single human individual actually is not separated from the universe. He is part of it, and the connection of this part with the rest of the cosmos is present in reality; it is broken only for our perception. At first we see this part as a being existing by itself because we do not see the cords and ropes by which the fundamental forces of the cosmos sustain our life. One remaining at this standpoint sees the part of the whole as a truly independently existing being, as a monad, who somehow receives information about the rest of the world from outside. But monism, as meant here, shows that one can believe in this independence only so long as what is perceived is not woven by thinking into the network of the world of concepts. When this happens, separate existence of parts is revealed as a mere appearance due to perceiving. Man can find his self-enclosed total existence within the universe only through the intuitive experience of thinking. Thinking destroys the appearance due to perceiving, inserting our individual existence into the life of the cosmos. The unity of the world of concepts, which contains the objective perceptions, also embraces the content of our subjective personality. Thinking shows us reality in its true character as a self-enclosed unity, whereas the manifoldness of perceptions is only its appearance determined by our organization. (cp. p. 29 ff.). Recognition of the reality in contrast to the appearance resulting from perceiving has always been the goal of human thinking. Science has striven to recognize perceptions as realities by discovering the laws that connect them. But where the view was held that connections ascertained by human thinking had only a subjective significance, the real reason for the unity of things was sought in some entity existing beyond the world to be experienced (an inferred God, will, absolute Spirit, etc.). And on this basis, in addition to knowledge of the connections that are recognizable through experience, one strove to attain a second kind of knowledge which would go beyond experience and would reveal the connection between experience and the ultimate entities existing beyond experience (metaphysics arrived at by drawing conclusions and not by experience). From this standpoint, it was thought that the reason we can grasp the connection of things through strictly applied thinking is that an original creator built up the world according to logical laws, and the source of our deeds was thought to be contained in the will of the creator. It was not realized that thinking encompasses both subjective and objective in one grasp, and that in the union of perception with concept full reality is mediated. Only as long as we consider in the abstract form of concepts the laws pervading and determining perceptions, do we deal in actual fact with something purely subjective. But the content of the concept, which is attained — with the help of thinking — in order to add it to perception, is not subjective. This content is not derived from the subject but from reality. It is that part of reality that our perceiving cannot reach. It is experience, but not experience mediated through perceiving. One unable to recognize that the concept is something real, thinks of it only in that abstract form in which he grasps it in his consciousness. But this separation is due to our organization, just as the separateness of perceptions is due to our organization. The tree that one perceives, has no existence by itself. It is only a part of the great organism of nature, and its existence is possible only in a real connection with nature. An abstract concept has no reality in itself, any more than a perception, taken by itself, has any reality. The perception is the part of reality that is given objectively, the concept is the part that is given subjectively (through intuition, cp. p. 32 ff.). Our spiritual organization tears reality into these two factors. One factor appears to perception, the other to intuition. Only the union of the two, that is, the perception fitted systematically into the universe, is full reality. If we consider the mere perception by itself, we do not have reality, but a disconnected chaos; if we consider by itself the law that connects perceptions, we are dealing with mere abstract concepts. The abstract concept does not contain reality, but thinking observation which considers neither concept nor perception one-sidedly, but the union of both, does.
Not even the most subjective orthodox idealist will deny that we live within a reality (that we are rooted in it with our real existence). He only questions whether we also reach ideally, i.e., in our cognition, what we actually experience. By contrast, monism shows that thinking is neither subjective nor objective, but is a principle embracing both sides of reality. When we observe with thinking, we carry out a process that in itself belongs in the sequence of real occurrences. By means of thinking we overcome — within experience itself — the one-sidedness of mere perceiving. We are not able through abstract conceptual hypotheses (through pure conceptual reflection) to devise the nature of reality, but when we find the ideas that belong to the perceptions we live within reality. The monist does not try to add something to our experience that cannot be experienced (a Beyond), but in concept and perception sees the real. He does not spin metaphysics out of mere abstract concepts; he sees in the concept, as such, only one side of reality, namely, that side which remains hidden from perceiving but having meaning only in union with perceptions. Monism calls forth in man the conviction that he lives in a world of reality and does not have to go beyond this world for a higher reality that cannot be experienced. The monist does not look for Absolute Reality anywhere but in experience, because he recognizes that the content of experience is the reality. And he is satisfied by this reality, because he knows that thinking has the power to guarantee it. What dualism looks for only behind the world of observation, monism finds within it. Monism shows that in our cognition we grasp reality, not in a subjective image which slips in between man and reality, but in its true nature. For monism the conceptual content of the world is the same for every human individual (cp. 33 p. ff.). According to monistic principles, the reason one human individual regards another as akin to himself is because it is the same world content that expresses itself in the other also. In the unitary world of concepts there are not as many concepts of lions as there are individuals who think of a lion, but only one concept, lion. And the concept which “A” adds to his perception of a lion is the same concept as “B” adds to his, only apprehended by a different perceiving subject (cp. p. 32). Thinking leads all perceiving subjects to the common ideal unity of all multiplicity. The one world of ideas expresses itself in them as in a multiplicity of individuals. As long as man apprehends himself merely by means of self-perception, he regards himself as this particular human being; as soon as he looks toward the idea-world that lights up within him and embraces all particulars, he sees absolute reality living and shining forth within him. Dualism defines the divine primordial Being as pervading and living in all men. Monism sees this common divine life in reality itself. The ideal content of another human being is also my content, and I regard it as a different content only so long as I perceive, but no longer when I think. In his thinking each man embraces only a part of the total idea-world, and to that extent individuals differ one from another by the actual content of their thinking. But these contents are within one self-enclosed whole, which encompasses the content of all men's thinking. In his thinking therefore, man takes hold of the universal primordial Being pervading all humanity. A life within reality filled with the content of thought is at the same time a life within God. The merely inferred, not to be experienced Beyond is based on a misunderstanding on the part of those who believe that the world in which we live does not contain within itself the cause and reason for its existence. They do not recognize that through thinking they find what they need to explain the perceptions. This is also why no speculation has ever brought to light any content that has not been borrowed from the reality that is given us. The God that is assumed through abstract conclusions is nothing but a human being transplanted into the Beyond; Schopenhauer's will is the power of human will made absolute. Hartmann's unconscious primordial Being. composed of idea and will. is a combination of two abstractions drawn from experience. Exactly the same is true of all other transcendent principles that are not based on thinking which is experienced.
In truth, the human spirit never goes beyond the reality in which we live, nor is there any need to do so, since everything we require in order to explain the world is within the world. If philosophers eventually declare that they are satisfied when they have deduced the world from principles they borrow from experience and transplant into an hypothetical Beyond, then the same satisfaction must also be possible, if the borrowed content is allowed to remain in this world where, for thinking to be experienced, it belongs. All attempts to transcend the world are purely illusory, and the principles transplanted from this world into the Beyond do not explain the world any better than those within it. And thinking, properly understood, does not demand any such transcendence at all, because a thought-content can seek a perceptual content, together with which it forms a reality only within the world, not outside it. The objects of imagination, too, are contents which are valid only if they become representations that refer to a perceptual content. Through this perceptual content they become part of reality. A concept that is supposed to be filled with a content from beyond the world given us, is an abstraction to which no reality corresponds. We can think out only concepts of reality; in order actually to find reality itself, we must also perceive. An absolute Being for which a content is devised is an impossible assumption when thinking is properly understood. The monist does not deny the ideal; in fact he considers a perceptual content, lacking its ideal counterpart, not to be a complete reality; but in the whole sphere of thinking he finds nothing that could make it necessary to deny the objective spiritual reality of thinking and therefore leave the realm which thinking can experience. Monism regards science that limits itself to a description of perceptions without penetrating to their ideal complements, as being incomplete. But it regards as equally incomplete all abstract concepts that do not find their complements in perceptions and nowhere fit into the network of concepts embracing the world to be observed. Therefore it can acknowledge no ideas that refer to objective factors lying beyond our experience, which are supposed to form the content of purely hypothetical metaphysics. All ideas of this kind which humanity has produced, monism recognizes as abstractions borrowed from experience; it is simply that the fact of the borrowing has been overlooked.
Just as little, according to monistic principles, could the aims of our action be derived from a Beyond outside mankind. Insofar as they are thought, they must originate from human intuition. Man does not make the purposes of an objective (existing beyond) primordial Being into his own individual purposes; he pursues his own, given him by his moral imagination. The idea that realizes itself in a deed, man detaches from the unitary idea-world, making it the foundation of his will. Consequently, what come to expression in his action are not commands projected from a Beyond into the world, but human intuitions that are within the world. For monism acknowledges no world ruler who sets our aims and directs our activity from outside. Man will find no such foundation of existence, whose decisions he must fathom in order to discover the aims toward which he is to guide his activity. He is referred back to himself. He himself must give content to his activity. If he seeks for the determining causes of his will outside the world in which he lives, then his search will be in vain. When he goes beyond the satisfaction of his natural instincts, for which Mother Nature has provided, then he must seek these causes in his own moral imagination, unless he finds it more convenient to let himself be determined by the moral imagination of others. This means: either he must give up being active altogether, or must act according to determinations he gives himself out of his world of ideas, or which others give him from that world. When he gets beyond his bodily life of instincts, and beyond carrying out the commands of others, then he is determined by nothing but himself. He must act according to an impulse produced by himself and determined by nothing else. This impulse is indeed determined ideally in the unitary idea world, but in actual fact it is only through man that it can be taken from that world and translated into reality. The reason for the actual translation of an idea into reality through man, monism finds only in man himself. For idea to become deed, man must first will before it can happen. Such will then has its foundation only in man himself. Therefore ultimately it is man who determines his own deed. He is free.
1st Addition to the Revised Edition, 1918: In the second part of this book the attempt has been made to give proof that freedom (spiritual activity) is to be found in the reality of human deeds. To do this it was necessary to separate from the total sphere of human deeds those actions that can be deemed free by unbiased self-observation. They are the deeds which prove to be the realization of ideal intuitions. No other deeds, if considered without prejudice, can be regarded as free. But unbiased self observation will lead man to recognize that it is inherent in his nature to progress along the path toward ethical intuitions and their realization. Yet this unprejudiced observation of man's ethical nature cannot arrive at an ultimate conclusion about freedom by itself. For if intuitive thinking had its source in some other being, if its being were not such as had its origin in itself, then the consciousness of freedom, which springs from morality, would prove to be an illusion. But the second part of this book finds its natural support in the first part, where intuitive thinking is presented as an inner, spiritual activity of man, which is experienced. To understand this nature of thinking in living experience is at the same time to recognize the freedom of intuitive thinking. And if one knows that this thinking is free, then one also recognizes that sphere of the will to which freedom can be ascribed. Acting human beings will consider that will as free to which the intuitive life in thinking, on the basis of inner experience, can attribute a self-sustaining essence. One unable to do this cannot discover any altogether indisputable argument for the acceptance of freedom. The experience which is referred to here finds intuitive thinking in consciousness, which has reality not only in consciousness. And thereby it is discovered that freedom is the characteristic feature of all deeds that have their source in the intuitions of consciousness.
2nd Addition to the Revised Edition, 1918: The content of this book is built upon intuitive thinking, of which the experience is purely spiritual, and through which, in cognition, every single perception is placed within reality. This book intends to present no more than can be surveyed through the experience of intuitive thinking. But it also intends to present the kind of thought which this experienced thinking requires. It requires that in the process of knowledge thinking is not denied as a self dependent experience. It requires that one does not deny its ability to experience reality in union with perceptions, instead of looking for reality only in a world lying outside this experience, an inferred world in relation to which the human activity of thinking would be something merely subjective. —
This characterizes thinking as the element through which man gradually enters spiritually into reality. (It ought not to be possible to confuse this world view, based on experienced thinking, with a mere rationalism.) On the other hand, it should be evident from the whole spirit of this presentation that for human knowledge, the perceptual element contains a reality-content only if it is grasped by thinking. What characterizes reality as reality cannot lie outside thinking. Therefore it must not be imagined that the physical kind of perceiving guarantees the only reality. What comes to meet us as perception is something man must simply expect on his life journey. All he can ask is: Is one justified in expecting, from the point of view resulting from the intuitively experienced thinking, that it is possible for man to perceive not only physically but also spiritually? This can be expected. For even though on the one hand intuitively experienced thinking is an active process taking place in the human spirit, on the other hand it is also spiritual perception grasped without a physical organ. It is a perception in which the perceiver is himself active, and it is an activity of the self which is also perceived. In intuitively experienced thinking man is transferred into a spiritual world as perceiver. What comes to meet him as perceptions within this world in the same way as the spiritual world of his own thinking comes to meet him, man recognizes as a world of spiritual perception. This world of perception has the same relationship to thinking as the world of physical perception has on the physical side. When man experiences the world of spiritual perception it will not appear foreign to him, because in intuitive thinking he already has an experience which is of a purely spiritual character. A number of my writings which have been published since this book first appeared, deal with such a world of spiritual perception. The Philosophy of Spiritual Activity lays the philosophical foundation for these later writings. For here the aim is to show that a properly understood experience of thinking is already an experience of spirit. For this reason it appears to the author that one able in all earnestness to enter into the point of view of The Philosophy of Spiritual Activity will not come to a standstill at the entry into the world of spiritual perception. It is true that by drawing conclusions from the content of this book it is not possible to derive logically what is presented in my later books. But from a living grasp of what in this book is meant by intuitive thinking, the further step will result quite naturally: the actual entry into the world of spiritual perception.