Referring back to the statement that seeing is limited to the visible qualities of some object, hearing to its audible qualities, etc., while the faculty of thought has everything for its object, we now understand this to mean that all objects have certain innumerable, but concrete, qualities which are perceptible by our senses, and in addition thereto the general spiritual quality of being thought of, understood, in short, of being the object of our faculty of thought.

This mode of cla.s.sifying all objects applies also to the faculty of thought itself. The spirit, or mind, is a bodily function connected with the senses which appear in various forms. Mind is thought generated at different times in different brains by different objects through the instrumentality of the senses. We may choose this mind as the object of special thought the same as all other things. Considered as an object, mind is a manysided and sense-perceived fact which in connection with a special function of the brain generates the general concept of "Mind" as the content of this special thought process. The object of thought is distinguished from its contents in the same way in which every object is distinguished from its mental image. The different kinds of motion perceived by the help of the senses are the object of a certain thought process and supply to it the idea of "motion." It is easier to understand that the mental image of some object perceived by the senses has a father and a mother, being begotten by our faculty of thought by means of some sense-perceived object, than it is to grasp the existence of that trinity which is born when our present thought experiences its own existence and thus creates a conception of its own self. This has the appearance of moving around in a circle. The object, the content and the function of thought apparently coincide. Reason deals with itself, considers itself as an object and is its own content. But nevertheless the distinction between an object and its concept, though less evident, is just as actual as in other cases. It is only the habit of regarding matter and mind as fundamentally different things which conceals this truth. The necessity to make a distinction compels us everywhere to discriminate between the object of sense perception and its mental concept. We are forced to do the same in the case of the faculty of thought, and thus we find it necessary to give the name of "Mind" to this special object of our sense perceptions. Such an ambiguity of terms cannot be entirely avoided in any science. A reader who does not cling to words, but rather seeks to grasp the meaning, will easily realize that the difference between being and thinking applies also to the faculty of thought, that the fact of understanding is different from the understanding of understanding. And since the understanding of understanding is again another fact, it will be permitted to call all spiritual things facts or sense perceptions.

Reason, or the faculty of thought, is therefore not a mystical object which produces the individual thought. On the contrary, it is a fact that certain individual thoughts are the product of perception gained in contact with certain objects and that these in connection with a certain brain operation produce the concept of reason. Reason as well as all other things of which we become aware has a two-fold existence: one as a phenomenon or sense-perception, the other as a concept. The concept of any thing presupposes a certain sense-perception of that thing, and so does the concept of reason. Since all men think as a matter of fact, every one has himself perceived reason as a part of reality, as a phenomenon, sense-perception or fact.

Our object, reason, by virtue of the fact that it partakes of the nature of the senses, has the faculty of transforming the speculative method, which tries to dip understanding out of the depths of the spirit without the help of sense-perception, into the inductive method, and vice versa of transforming the inductive method, which desires to arrive at conclusions, concepts, or understanding exclusively by means of sense-perception, into the speculative method, by virtue of its simultaneous spiritual nature. Our problem is to a.n.a.lyze the concept of thought, or of the faculty of thought, or of reason, of knowing, of science, by means of thought.

To produce thoughts and to a.n.a.lyze them is the same thing inasmuch as both actions are functions of the brain. Both have the same nature. But they are different to the same extent that instinct differs from consciousness. Man does not think originally because he wants to, but because he must. Ideas are produced instinctively, involuntarily. In order to become fully aware of them, to place them within the grasp of knowing and willing, we must a.n.a.lyze them. From the experience of walking, for instance, we derive the idea of walking. To a.n.a.lyze this idea means to solve the question, what is walking generally considered, what is the general nature of walking? We may answer: Walking is a rythmical motion from one place to another, and thus we raise the instinctive idea to the position of a conscious a.n.a.lyzed idea. An object is not consciously, theoretically, understood, until it has been a.n.a.lyzed. In examining what elements const.i.tute the concept of walking, we find that the general attribute of that experience which we agree in calling "walking" is a rythmical motion. In actual experience steps may be long or short, may be taken by two feet or by more, in brief may be varied. But as a concept walking is simply a rythmical motion, and the a.n.a.lysis of this concept furnishes us with the conscious understanding of this fact. The concept of light existed long before science a.n.a.lyzed it, before it was understood that undulations of the ether form the elements which const.i.tute the concept of light. Instinctive and a.n.a.lytical ideas differ in the same way in which the thoughts of every day life differ from the thoughts of science.

The a.n.a.lysis of any idea and the theoretical a.n.a.lysis of any object, or of the thing which suggested the idea, is one and the same. Every idea corresponds to some real object. Ludwig Feuerbach has demonstrated that even the concepts of G.o.d and immortality are reflections of real objects which can be perceived by the senses. For the purpose of a.n.a.lyzing such ideas as animal, light, friendship, man, etc., the phenomena, the objects, such as animals, friendships, men, and lights, are a.n.a.lyzed.

The object which serves for the a.n.a.lysis of the concept "animal" is no more any single animal, than the object of the concept "light" is any single light. These concepts comprise cla.s.ses, things in general, and therefore the question, or the a.n.a.lysis, of what const.i.tutes the animal, the light, friendship, must not deal with any concrete, but with the abstract elements of the whole cla.s.s.

The fact that the a.n.a.lysis of a concept and the a.n.a.lysis of its object appear as two different things is due to our faculty of being able to separate things into two parts, viz., into a practical, tangible, perceptible, concrete thing and into a theoretical mental, thinkable, general thing. The practical a.n.a.lysis is the premise of the theoretical a.n.a.lysis. The individually perceptible animals serve us as a basis for the a.n.a.lysis of the animal concept, the individually experienced friendships as the basis for the a.n.a.lysis of the concept of friendship.

Every idea corresponds to an object which may be practically separated into its component parts. To a.n.a.lyze a concept is equivalent, therefore, to a.n.a.lyzing a previously experienced object by theoretical means. The a.n.a.lysis of a concept consists in the understanding of the common or general faculties of the concrete parts of the a.n.a.lyzed object. That which is common to the various modes of walking, the rythmical motion, const.i.tutes the concept of walking, that which is common to the various manifestations of light const.i.tutes the concept of light. A chemical factory a.n.a.lyzes objects for the purpose of obtaining chemicals, while science a.n.a.lyzes them for the purpose of obtaining their concepts.

The special object of our a.n.a.lysis, the faculty of thought, is likewise distinguished from its concept. But in order to be able to a.n.a.lyze this concept, we must a.n.a.lyze the object. It cannot be a.n.a.lyzed chemically, for not everything is a matter of chemistry, but it may be a.n.a.lyzed theoretically or scientifically. As we have already stated, the science of understanding deals with all objects. But all objects which this science may wish to a.n.a.lyze theoretically, must first be handled practically. According to their special natures, they must either be handled in various ways, or carefully inspected, or scrutinized by intent listening, in short they must be thoroughly experienced in some way.

It is a fact of experience that men think. The object or suggestion is furnished by facts, and we then derive the concept instinctively. Thus, to a.n.a.lyze the faculty of thought means to find that which is common or general to the various personal and temporary processes of thought. In order to follow this study by the methods of natural science, we require neither physical instruments nor chemical reagents. The sense perception which is indispensable for every scientific understanding, is so to say present in this case _a priori_, without further experience.

Every one possesses the object of our study, the fact of thought faculty and its experience, in the memories of himself or herself.

We have seen that thought like any other activity as well as its scientific a.n.a.lysis is everywhere developing the general or abstract out of particular and concrete sense perceptions. We now express this in the following words: The common feature of all separate thought-processes consists in their seeking the general character or unity which is common to all objects experienced in their manifold variety by sense perceptions. The general element which is common to the different animals, or to the different manifestations of light, is that which const.i.tutes the general animal or light concept. The general is the nature of all concepts, of all understanding, all science, all thought processes. Thus we arrive at the understanding that the a.n.a.lysis of the faculty of thought reveals its nature of finding that which is general and common to concrete and distinct things. The eye studies the visible, the ear the audible, and our brain that which is generally conceivable.

We have seen that thought like any other activity requires an object; that it is unlimited in the choice of its objects, because all things may become the objects of thought; that these objects are perceived in manifold forms by various senses; and that they are transformed into simple ideas by extricating that which they possess in common, which is similar, which is general in them. If we apply this experienced understanding of the general method of thought processes to our special object, the faculty of thought, we realize that we have thus solved our problem, because all we were looking for was the general method of the thought process.

_If the development of the general out of the concrete const.i.tutes the general method by which reason arrives at understanding, then we have fully grasped reason as the faculty of deriving the general out of the concrete._

Thinking is a physical process and it cannot exist or produce anything without materials any more than any other process of labor. My thought requires some material which can be thought of. This material is furnished by the phenomena of nature and life. These are the concrete things. In claiming that the universe, or all things, may be the object of thought, we simply mean that the materials of the thought process, the objects of the mind, are infinite in quant.i.ty and quality. The materials which the universe furnishes for our thought are as infinite as s.p.a.ce, as eternal as time, and as absolutely manifold as the nature of these two forms of being. The faculty of thought is a universal faculty in so far as it enters into relations with all things, all substances, all phenomena, and thus generates thought. But it is not absolute, since it requires for its existence and action the previous presence of matter. Matter is the boundary, beyond which the mind cannot pa.s.s. Matter furnishes the background for the illumination of the mind, but is not consumed in this illumination. Mind is a product of matter, but matter is more than a product of mind, being perceived also through the five senses and thus brought to our notice. We call real, objective products, or "things themselves" only such products as are revealed to us simultaneously by the senses and the mind.

Reason is a real thing only in so far as it is perceived by the senses.

The perceptible actions of reason are revealed in the brain of man as well as in the world outside of it. For are not the effects tangible by which reason transforms nature and life? We see the successes of science with our eyes and grasp them with our hands. It is true that science or reason cannot produce such material effects out of themselves. The world of sense perceptions, the objects outside of the human brain, must be given. But what thing is there that has any effects "in itself?" In order that light may shine, that the sun may warm, and revolve in its course, there must be s.p.a.ce and other things which may be lighted and warmed and pa.s.sed. In order that my table may have color, there must be light and eyes. And everything else which my table is besides, it can be only in contact with other things. Its being is just as manifold as those various contacts or relations. In short, the world consists only in its interrelations. Any thing that is torn out of its relations with the world ceases to exist. A thing is anything "in itself" only because it is something for other things, by acting or appearing in connection with something else.

If we wish to regard the world in the light of the "thing itself," we shall easily see that the world "itself" and the world as it appears, the world of phenomena, differ only in the same way in which the whole differs from its component parts. The world "itself" is nothing else but the sum total of its phenomena. The same holds good of that part of the world phenomena which we call reason, spirit, faculty of thought.

Although we distinguish between the faculty of thought and its phenomena or manifestations, yet the faculty of thought "itself," or "pure"

reason, exists in reality only in the sum total of its manifestations.

Seeing is the physical existence of the faculty of sight. We possess the whole only by means of its parts, and we can possess reason, like all other things, only by the help of its effects, by its various thoughts.

But we repeat that reason does not precede thought in the order of time.

On the contrary thoughts generated by perceptible objects serve as a basis for the development of the concept of the faculty of thought. Just as the understanding of the world movements has taught us that the sun is not revolving around the earth, so the understanding of the thought process tells us that it is not the faculty of thought which creates thought, but vice versa, that the concept of this faculty is created out of a series of concrete thoughts. Hence the faculty of thought practically exists only as the sum total of our thoughts, just as the faculty of sight exists only through the sum of the things that we see.

These thoughts, this practical reason, serve as the material out of which our brain manufactures the concept of "pure" reason. Reason is necessarily impure in practice, which means that it must connect itself with some object. Pure reason, or abstract reason without any special content, cannot be anything else but the general characteristic of all concrete reasoning processes. We possess this general nature of reason in two ways: In an impure state, that is as practical and concrete phenomenon, consisting of the sum of our real perceptions, and in a pure state, that is theoretically or abstractly, in the concept. The phenomenon of reason is distinguished from reason "itself" just as the real animals are distinguished from the concept of the animal.

Every actual reasoning process is based on some real object which has many qualities like all things in nature. The faculty of thought extracts from this many-sided object those properties which are general or common with it. A mouse and an elephant, as the objects of our reasoning activity, lose their differences in the general animal concept. Such a concept combines many things under one uniform point of view, it develops one general idea out of many concrete things. Since understanding is the general or common quality of all reasoning processes, it follows that reason in general, or the general nature of the reasoning process, consists in abstracting the general ideal character from any concrete thing perceptible by the help of the senses.

Reason being unable to exist without some objects outside of itself, it is understood that we can perceive "pure" reason, or reason "itself,"

only by its practical manifestations. We cannot find reason without objects outside of it with which it comes in contact and produces thought, any more than we can find any eyes without light. And the manifestations of reason are as varied as the objects which supply its material. It is plain, then, that reason has no separate existence "in itself," but that on the contrary the concept of reason is formed out of the material supplied by the senses.

Mental processes appear only in connection with perceptible phenomena.

These processes are themselves phenomena of sense perception which, in connection with a brain process, produce the concept of the faculty of thought "itself." If we a.n.a.lyze this concept, we find that "pure" reason consists in the activity of producing general ideas out of concrete materials, which include so-called immaterial thoughts. In other words, reason may be characterized as an activity which seeks for unity in every multiplicity and equalizes all contrasts whether it deals with the many different sides and parts of one or of more objects. All these different statements describe the same thing in different words, so that the reader may not cling to the empty word, but grasp the living concept, the manifold object, in its general nature.

Reason, we said, exists in a "pure" state as the development of the general out of the special, of the abstract out of concrete sense perceptions. This is the whole content of pure reason, of scientific understanding, of consciousness. And by the terms "pure" and "whole" we simply indicate that we mean the general content of the various thought processes, the general form of reason. Apart from this general abstract form, reason, like all other things, has also its concrete, special, sense form which we perceive directly through our experience. Hence our entire process of consciousness consists in the experience of the senses, that is in the physical process, and its understanding.

Understanding is the general reflection of any object.

Consciousness, as the Latin root of the word indicates, is the knowledge of being in existence. It is a form, or a quality, of existence which differs from other forms of being in that it is aware of its existence.

Quality cannot be explained, but must be experienced. We know by experience that consciousness includes along with the knowledge of being in existence the difference and contradiction between subject and object, thinking and being, between form and content, between phenomenon and essential thing, between attribute and substance, between the general and the concrete. This innate contradiction explains the various terms applied to consciousness, such as the organ of abstraction, the faculty of generalization or unification, or in contradistinction thereto the faculty of differentiation. For consciousness generalizes differences and differentiates generalities. Contradiction is innate in consciousness, and its nature is so contradictory that it is at the same time a differentiating, a generalizing, and an understanding nature.

Consciousness generalizes contradiction. It recognizes that all nature, all being, lives in contradictions, that everything is what it is only in co-operation with its opposite. Just as visible things are not visible without the faculty of sight, and vice versa the faculty of sight cannot see anything but what is visible, so contradiction must be recognized as something general which pervades all thought and being.

The science of understanding, by generalizing contradiction, solves all concrete contradictions.

III

THE NATURE OF THINGS

In so far as the faculty of understanding is a physical object, the knowledge of its nature is a matter of physical science. But in so far as we understand all things by the help of this faculty, the science of understanding becomes metaphysics. Inasmuch as the scientific a.n.a.lysis of reason reverses the current conception of its nature, this specific understanding necessarily reverses our entire world philosophy. With the understanding of the nature of reason, we arrive at the long sought understanding of the "nature of things."

We wish to know, understand, conceive, recognize all things in their very nature, not in their outward appearance. Science seeks to understand the nature of things, or their true essence, by means of their manifestations. Every thing has its own special nature, and this nature is not seen, or felt, or heard, but solely perceived by the faculty of thought. This faculty explores the nature of all things just as the eye explores all that is visible in things. Just as the nature of sight is understood by the theory of vision, so the nature of things in general is understood by the theory of understanding.

It is true that it sounds contradictory to say that the nature of a thing does not appear to the eye, but to the faculty of thought, and at the same time to imply that the opposite of appearance, nature, should appear. But we here refer to the nature of a thing as a phenomenon in the same way in which we referred to the mind as a perception of the senses, and we shall demonstrate further on that every being is a phenomenon, and every phenomenon is more or less of an essential thing.

We have seen that the faculty of thought requires for its vital activity an object, or raw material. The effect of reasoning is seen in science, no matter whether we understand the term science in its narrow cla.s.sical sense or in its broadest meaning of any kind of knowledge. The phenomena of sense perception const.i.tute the general object or material of science. Sense perceptions arise from infinite circulation of matter.

The universe and all things in it consist of transformations of matter which take place simultaneously and consecutively in s.p.a.ce and time. The universe is in every place and at any time itself, new, and present for the first time. It arises and pa.s.ses away, pa.s.ses and arises under our very hands. Nothing remains the same, only the infinite change is constant, and even the change varies. Every particle of time and s.p.a.ce brings new changes. It is true that the materialist believes in the permanency, eternity, indestructibility of matter. He teaches us that not the smallest particle of matter has ever been lost in the world, that matter simply changes its forms eternally, but that its nature lasts indestructibly through all eternity. And yet, in spite of all distinctions between matter itself and its perishable form, the materialist is on the other hand more inclined than any one else to dwell on the ident.i.ty of matter and its forms. Inasmuch as the materialist speaks ironically of formless matter and matterless forms, in the same breath with perishable forms of imperishable matter, it is plain that materialism is not informed any more than idealism as to the relation of content to form, of a phenomenon to the essential nature of its subject. Where do we find such eternal, imperishable, formless matter? In the world of sense perceptions we never meet anything but forms of perishable matter. It is true that there is matter everywhere.

Wherever anything pa.s.ses away, something new instantly arises. But nowhere has any h.o.m.ogeneous, unchangeable matter enduring without any form, ever been discovered. Even a chemically indivisible element is only a relative unit in its actual existence, and in extension of time as well as in extension through s.p.a.ce it varies simultaneously and consecutively as much as any organic individual which also changes only its concrete forms, but remains the same in its general nature from beginning to end. My body changes continually its fleshy tissue, bones, and every other particle belonging to it, and yet it always remains the same. What const.i.tutes, then, this body which is distinguished from its transient form? It is the sum total, in a generalized way, of all its varied concrete forms. Eternal and imperishable matter exists in reality only as the sum total of its perishable forms. The statement that matter is imperishable cannot mean anything but that there will always and everywhere be matter. It is just as true to say that matter is imperishable and merely changes its forms, as it is to say that matter exists only in its changing forms, that it is matter which changes and that only the change is eternal. The terms "changeable matter" and "material change" are after all only different expressions for the same thing.

In the practical world of sense perceptions, there is nothing permanent, nothing h.o.m.ogeneous, nothing beyond nature, nothing like a "thing itself." Everything is changing, pa.s.sing, phantomlike, so to say. One phantom is chased by another. "Nevertheless," says Kant, "things are also something in themselves," for otherwise we should have the absurd contradiction that there could be phenomena without things that produce them. But no! A phenomena is no more and no less different from the thing which produces it than the stretch of a twenty-mile road is different from the road itself. Or we may distinguish between a knife and its blade and handle, but we know that there would be no knife if there were no blade and no handle. The essential nature of the universe is change. Phenomena appear, that is all.

The contradiction between the "thing itself," or its essence, and its outward appearance is fully solved by a complete critique of reason which arrives at the understanding that the human faculty of thought may generalize any number of varied sense perceptions under one uniform point of view, by singling out the general and equivalent forms and thus regarding everything it may meet as a concrete part of one and the same whole.

In other words, the relative and transient forms perceived by our senses serve as raw material for our brain activity, which abstracts the general likeness out of the concrete forms and systematizes or cla.s.sifies them for our consciousness. The infinite variety of sense perceptions pa.s.ses in review before our subjective mind, and it constructs out of the multiplicity the unity, out of the parts the whole, out of the phenomena the essential nature, out of the perishable the imperishable, out of the attributes the subject. The essence, the nature of things, the "thing itself" is an ideal, a spiritual conception. Consciousness knows how to make sums out of different units.

It can take any number of units for its sums. The entire multiplicity of the universe is theoretically conceived as one unit. On the other hand, every abstract sum consists in reality of an infinite number of sense perceptions. Where do we find any indivisible unit outside of our abstract conceptions? Two halves, four fourths, eight eighths, or an infinite number of separate parts form the raw material out of which the mind fashions the mathematical unit. This book, its leaves, its letters, or their parts, are they units? Where do I begin, where do I stop? In the same way, I may call a library with many volumes, a house, a farm, and finally the whole universe, a unit. Is not everything a part, is not every part a thing? Is the color of a leaf less of a thing than that leaf itself? Perhaps some would call the color simply an attribute and the leaf its substance, because there might be a leaf without color, but no color without a leaf. But as surely as we exhaust a heap of sand by scattering it, just as surely do we remove all the substance of a leaf when we take away its attributes one after the other. Color is only the sum of reactions of leaf, light, and eye, and so is all the rest of the matter of a leaf an aggregate of interactions. In the same way in which our reason deprives a leaf of its color attributes and sets it apart as a "thing itself," may we continue to deprive that leaf of all its other attributes, and in so doing we finally take away everything that makes the leaf. Color is in its nature no less a substance than the leaf itself, and the leaf is no less an attribute than its color. As the color is an attribute of a leaf, so a leaf is an attribute of a tree, a tree an attribute of the earth, the earth an attribute of the universe.

The universe is the substance, substance in general, and all other substances are but its attributes. And this world-substance reveals the fact that the nature of things, the "thing itself" as distinguished from its manifestations, is only a concept of the mind.

In its universal search from the attribute to the substance, from the relative to the absolute, from the appearance of things to the true things, the mind finally arrives at the understanding that the substance is nothing but a sum of attributes collected by brain activity, and that the mind itself, or reason, is a substantial being which creates abstract mental units out of a mult.i.tude of sense perceptions and conceives of the universe as an absolute whole, as an independent "thing itself," by adding all its transient manifestations. In turning away full of dissatisfaction from attributes, searching restlessly after the substance, throwing aside phenomena, and forever groping for truth, for the nature of things, for the "thing itself," and in finally realizing that this substantial truth is merely the sum of all socalled untruths, the totality of all phenomena, the mind proves itself to be the creator of the abstract concept of substance. But it did not create this concept out of nothing. On the contrary, it generated the concept of a world substance out of attributes, it derived truth out of manifestations of things.

The idealist conception that there is an abstract nature behind phenomena which materialises itself in them, is refuted by the understanding that this hidden nature does not dwell in the world outside of the human mind, but in the brain of man. But since the brain differentiates between phenomena and their nature, between the concrete and the general, only by means of sense perception, it cannot be denied that the distinction between phenomena and their nature is well founded; only the essential nature of things is not found back of phenomena, but by means of phenomena. This nature is materially existent and our faculty of thought is a real and natural one.

It is true of spiritual things as well as of physical ones, in fact it is true of all things, metaphysically speaking, that they are what they are, not "in themselves," not in their abstract nature, but in contact with other things, in reality. In this sense one might say that things are not what they seem, but manifest themselves because they are existent, and they manifest themselves in as many different ways as there are other things with which they enter into relations of time and s.p.a.ce. But the statement that things are not what they seem requires, in order to be rightly understood, the modification that whatever manifests itself, exists in nature, and its existence is limited by its manifestations. "We cannot perceive heat itself," says a book on physics written by Professor Koppe, "we merely conclude from its manifestations that it is present in nature." Thus reasons a naturalist who seeks to understand a thing by practical and diligent study of its manifestations, but who seeks refuge in the speculative belief in a hidden "thing itself" whenever a lack of understanding of the fundamentals of logic embarra.s.ses him. We, on the contrary, conclude that there is no such thing as "heat itself," since it cannot be found, in nature, and we conceive of heat as effects of matter which the human brain translated into the conception of "heat itself." Because science was, perhaps, as yet unable to a.n.a.lyse this conception, the professor says we cannot perceive the natural object which gives rise to this conception. "Heat itself" is simply composed of the sum total of its manifold effects, and there is nothing else to it. The faculty of thought generalizes this variety of effects under the concept of heat in general. The a.n.a.lysis of this conception, the discovery of the general character of the various manifestations of heat, is the function of inductive science. But the conception of heat separated from its effects is a speculative idea, similar to Lichtenberg's knife without handle and blade.

The faculty of thought in touch with sense perceptions produces the nature of things. But it produces them no more independently of things outside than do the eye, the ear, or any other sense of man. It is not the "things themselves" which we see or feel, but their effects on our eyes, hands, etc. The faculty of reason to generalize different perceptions of the eye permits us to distinguish between concrete sights and sight in general. The faculty of thought conceives of any concrete sight as an object of sight in general. It furthermore distinguishes between subjective and objective sight perceptions, the latter being sights which are visible not alone to the individual eye, but to eyesight in general. Even the visions of a spiritualist, or such subjective impressions as forked lightning, circles of fire, caused by excited blood of closed eyes, serve as objects for the critical consciousness. A glittering object revealed by bright sunlight miles away is no more and no less tangible in substance, no more and no less true, than any optical illusion. A man whose ear is tingling hears something, though it is not the tinkling of bells. Every sense perception is an object, and every object is a sense perception. The object of any subjective mind is a pa.s.sing manifestation, and every objective perception is but a perishable subject. The object of observation may exist in a more tangible, less approachable, more stable, or more general form, but it is not a "thing itself." It may be perceived not alone by my eyes, but also by those of others, not by the eyes, but also by the feeling, the hearing, the taste, etc. And it may be noticed not alone by men, but also by other objects. But nevertheless it appears only as a manifestation, it is different in different places, it is not today what it is tomorrow. Every existence is relative, in touch with other things, and entering into different relations of time and s.p.a.ce with them.

Every sense perception is an actual and natural object. Truth exists in the form of natural phenomena, and whatever is, is true. Substance and attribute are only terms for certain relations. They are not contradictions, and, as a matter of fact, all contradictions disappear before our faculty of generalization and differentiation. For this faculty reconciles all contradictions by finding a general quality in all differences. Existence, or universal truth, is the general object, the raw material, of the faculty of thought. This material is of the utmost variety and supplied by the senses. The senses reveal to us the substance of the universe in the forms of concrete qualities, in other words, the nature of perceptible matter is revealed to the faculty of thought through a variety of concrete forms. It is not perceived as a general essence, but only through interdependent phenomena. Out of the interdependence of the sense perceptions with our faculty of thought there arise quant.i.ties, general concepts, things, true perceptions, or understood truths.

Essence and truth are two terms for the same thing. Truth, or the essence and nature of things, is a theoretical concept. As we have seen, we receive impressions of things in two ways, viz., a sense impression and a mental impression, the one practical, the other theoretical.

Practice furnishes us with the sense impression, theory with the mental nature of things.

Practice is the premise of theory, sense perception the premise of the nature which is also called the truth. The same truth manifests itself in practice either simultaneously or consecutively in the same place or in different places. It exists theoretically as a h.o.m.ogeneous conception.