The Contemporary History of the Western Philosophy

Johann Gottlieb Fichte


The Early Period:

Johann Fichte was born as a son of a very poor ribbon weaver in the village called Rammenau in Sachsen (Saxony in Eastern Germany). When he was a small child, he learned how to weave ribbon and watch geese and helped his family. Johann was a very unusual child and was able to retell the sermon as he very carefully listened to the preacher 's talk. One day, a wealthy farmer from the neighboring village was not able to be to attend the church service on time one Sunday. So someone told him that he should ask that child who attended the geese. As the wealthy farmer heard that child recite the sermon back to him exactly without any problem to him, he was so impressed with his potential that he sponsored this child's education.
Having graduated from the Gymnasium, Johann Fichte studied philosophy, classical literature and theology at Jena and Leipzig University. When his sponsor died and Fichte's parents could not provide Johann the financial support to continue his study, Johann Fichte went to Zurich and became a tutor for the children of a wealthy merchant. During his stay in Zurich, Johann Fichte had a chance to get acquainted with an extremely intelligent, strong-charactered young lady called Johanna Rahn and was deeply attracted by her. She later married Johann Fichte and helped him in various ways to further his philosophy throughout his life. Since the parents of the children he tutored were rather vulgar and uninteresting people, Johann Fichte left Zurich and went back to Leipzig in 1790. In order to make his living, he was commissioned to tutor a college student of the well-to-do family in Kant's philosophy, Johann Fichte for the first time himself studied Kant and his philosophy intensively for this purpose. This encounter of Fichte with Kant's publications made a decisive influence on Fichte and came to determine his entire life.
In his letter to his then fiancé and later his wife, Johanna Rahn, Fichte wrote, "I have finally acquired a most noble morality and instead of concerning myself with the external things, I am devoting myself to my own inner self. Thus I have been experiencing the peace of mind which I have never before experienced and am living a very happy life." To one of his friends, Johann Fichte also wrote, " is incredulous how profoundly Kant's philosophy, his moral philosophy in particular, has influenced the total system of one man's thinking and how decidedly Kant's philosophy has initiated a revolution in my total philosophical thought. Since I read the Critique of Practical Reason, I am living in a totally different world. The principles that I hitherto believed to be absolutely certain have been totally uprooted and destroyed. What I previously thought to be impossible to explain, for example, absolute Freedom and Moral Obligation are apodeictically demonstrated. An exhaustible joy fills me. It is incredible how great and overwhelming the admiration and the strength to humanity this system gives."
Next year, Fichte became acquainted with Kant in person in Königsberg in East Prussia (today's Karingrad). In the hope that his devotion to Kant's philosophy and his ability in philosophy be recognized by Kant himself, Johann Fichte wrote Versuch einer Kritik aller Offenbarung (A Attempt of the Critique of All Revelations) in 1792, in which Kant's philosophical thought was applied to religious philosophy. Since Kant had not yet published his book on religious philosophy (his Die Religion innerhalb der Grenzen der blossen Vernunft appeared in 1798), Kant read Fichte's work and appreciated his philosophical gift, so much so that Kant found a job tutoring in Danzig and helped Fichte's work to be published. In 1792 this opus was published anonymously, i.e., but without the author's name due to some unknown error. Because the position of the book was so close to Kant's philosophy, the academic world thought that the author of Versuch einer Kritik aller Offenbarung was Kant. Once it was revealed that the book was written by Fichte instead, he became instantaneously famous.
Johann Fichte went back to Zurich to marry Johanna and also got acquainted with Pestalozzi, the famous Swiss pedagogist. During his stay in Zurich, Fichte wrote books on the French Revolution and on the freedom of the press. During his early period, Fichte was deeply involved in practical philosophy.
In 1794 Johann Fichte was appointed as the successor to Reinhold, as Reinhold moved to Kiel University. For five years, till 1799, Johann Fichte was at Jena University devoting himself to the development of his own philosophical system and also exercised a profound influence on his students. On first appearance his first opus looks to be a theoretical philosophy:
Über den Begriff der Wissenschaftslehre
Grundlage der gesamten Wissenschaftslehre in 1794.

Further, Fichte wanted to make his system more complete and more intelligible, thus he wrote:
Erste Einleitung in die Wissenschaftslehre
Zweite Einleitung in die Wissenschaftslehre
Versuch einer neuen Darstellung der Wissenschaftslehre
in 1797.

Fichte also wrote books on practical philosophy:
Grundlage des Naturrechts nach Prinzipien der Wissenschaftslehre in 1796.
Das System der Sittenlehre nach der Prinzipien der Wissenschaftslehre in 1798.

In 1799 the so-called Der Atheismusstreit (the controversy over atheism) took place in Jena whereby the bureaucrats accused Fichte of being an atheist.
Über den Grund unseres Glaubens an eine göttliche Weltregierung in 1798.

Johann Fichte argues that the moral order in the world is the most certain proof for the existence of God: The very moral order which is fully active and effective in us is no other than the proof that God exists. We need God solely as the universal moral order and need nothing else in our religion. Beyond and above this universal moral order, according to Fichte, there exists no basis to recognize a Special Being as the (mechanical, efficient) Cause of this universe. Anyone who tries to acknowledge and ascribe Him a certain "consciousness" and "person" in this special Being is to make God rather a finite being without being aware of what he is doing. The self that has consciousness is, according to Fichte, a finite, limited, individual ego.
Against Fichte's moral argument for God as the Ground for the moral order of this universe (which denies Him consciousness and person, too,), the Government of Kursachsen (Kursaxony), whose capital was Dresden, decided to confiscate Fichte's books and placed an official complaint to the Government of Weimar that Atheism was taught at the University in Jena, which was a territory of Weimar Republic. In stead of taking a consoling attitude to this political uproar, Fichte was being extremely outraged and wrote a second article with a more radical tone:
Appellation an ad Publikum in 1799
Gerichtliche Verantwortung gegen die Anklage des Atheismus

The Government of Weimar wanted to settle this diplomatic friction rather quietly without both antagonizing the Government of Kursachsen and firing Fichte from the University. Nevertheless, Fichte's personality did not accept such a procedure (Wasn't he childish? Yes, Indeed he was.) and he wrote a radical complaint to the Government. Everyone concerned in the Government of Weimar got furious with Fichte and naturally fired him.
In Berlin Fichte wrote books and lectured as a private citizen (he could not get a teaching position due to that "scandal"). During the Berlin period, Fichte tended to be more religious and mystical in his philosophical thinking. The officials in Berlin were friendly to Fichte, people were enthusiastic, and Fichte enjoyed close friendships with such Romantic writers as the brothers Schlegel, Thiek and Schleiermacher.
Fichte wrote:
Die Bestimmung des Menschen
Der geschlossene Handelsstaat
in 1800
Darstellung der Wissenschaftslehre in 1801
Die Grundzüge des gegenwärtigen Zeitalters
Über das Wesen des Gelehrten
Die Anweisung zum seeligen Leben oder die Religionslehre
in 1806

In 1806 and 1807 Prussia fought against Napoleon and lost the war and Berlin was also occupied by the French army. Fichte gave a series of lectures appealing to Patriotism for the Germans:
Reden an die deutsche Nation in 1808

In 1810 a new university was founded in Berlin and Fichte became professor there.
In 1818 the so-called Freiheitskrieg (The War of Liberation) broke out, Paris was occupied in March and Napoleon was sent to St. Helena. Fichte became a victim of this war, for Johanna Fichte was working as a nurse at the military hospital and contracted an infectious disease from soldiers who were patients there. Fichte also became fatally infected.
Die Tatsachen des Bewußtseins

(his lectures at Berlin University in 1810) in 1817
This is a good introduction to Fichte's philosophy.

Epistemology and Universal Ontology:

Über den Begriff der Wissenschaftslehre
Grundlage der gesamten Wissenschaftslehre
Grundriß der Eigentümlichen der Wissenschaftslehre (1795)
Erste Einleitung in die Wissenschaftslehre
Zweite Einleitung in die Wissenschaftslehre
Versuch einer neuen Darstellung der Wissenschaftslehre
Die Bestimmung des Menschen (1800)
Darstellung der Wissenschaftslehre (1801)
Die Tatsachen der Bewußtseins (1810/1817)


Zurückforderung der Denkfreiheit
Über die französische Revolution
Grundlage des Naturrechts [1796]
System der Sittenlehre [1798]
Der geschlossene Handelsstaat [1800]
Die Grundzüge des gegenwärtigen Zeitalters
Über das Wesen des Gelehrten
Reden an die deutsche nation [1808]
Vorlesungen über die Staatslehre [1818/1820]

The Religious Philosophy:

Versuch einer Kritik aller Offenbarung [1792]
Über den Grund unseres Glaubens an eine göttlichen Wetregierung [1798]
Appellation an das Publikum Gerichtliche Verantwortung gegen die Anklage des Atheismus [1799]
Die Anweisung zum seeligen Leben oder die Religionslehre [1807]


1. Die Wissenschaftslehre
(The doctrine of Science)

1. The Objectives
Unfisnished Business of Kant
Completion of Idealism
1.-i. The task unfulfilled by Kant's philosophy: Radicalization of Idealism:

According to Fichte, Kant's greatest merit was in his discovery and establishment of Transcendental Idealism (whereby the emphasis is on Idealism). Fichte contended that what Kant had accomplished by Transcendental Idealism was to reverse the philosophical "common sense" orientation such that our thought or understanding (reason) is the source of the universal and necessary validity of knowledge, and not the knowledge's relatedness to nature (the external world). In other words, Kant elucidated that the idea determines the object and not that the object determines the idea (unlike the assumption of the British Empiricism). Our knowledge does not derive from the external world, but no doubt being related to the external world, our knowledge possesses the universal and necessary validity (as the criterion of its truth) by means of our reason (our mind or consciousness).
In other words, Kant "divorced" the pursuit of knowledge (=philosophy) from its immersion in the external world (nature) and brought philosophy back to the inquiry into the Self itself or consciousness. This is in a senses a regression to philosophy of self and consciousness. Nevertheless, Fichte thought that most philosophers misunderstood the spirit of Kant's system and intention and adhered to the surface, namely the uses of the words. They were absolved in the thing in itself or the material elements and oversaw that Kant purported the opposite. Kant's interpreters intended to read their own prejudices into Kant's philosophy so that they took Kant's objections for Kant's thought. In other words, they merely made Kant's philosophy once again a dogmatism, while Kant had attempted to destroy dogmatism. For example, Reinhold's interpretation of Kant is a strange conjecture of a naive dogmatism and a decisive idealism. According to Fichte, however, that is inconceivable for the originator of such a great philosophy. Fichte thought that what Kant intended to accomplish in his philosophy was the unfinished business and Fichte's task was, so he conceived, to radicalize Kant's position and complete his intention by eliminating the dogmatic elements.

I.-ii. A systematic completion of idealism:

Fichte viewed that the biggest problem of Kant's philosophy consists in a "cleft" in his system, i.e., the "logical inconsistency" (according to Fichte) in Kant's philosophy. As Fichte saw it, Kant indeed established the transcendental philosophy to justify the objectivity of our knowledge of nature, and yet he failed to provide the philosophical foundation for Transcendental Idealism itself. What was left by Kant therefore, according to Fichte, was to establish the unity and integration of the system in the transcendental philosophy. The completion of Transcendental Idealism was to Fichte Die Wissenschaftslehre. According to Johann Fichte, in order to accomplish this, he must demonstrate that it is possible to logically deduce the entire system of philosophy from one and the only one principle. This was the subjectivity or "Self." In this sense, despite Fichte's contention, Fichte did not perfect Kant's philosophy as a mere epigonen (imitator and follower), but ended up with developing his own, considerably different philosophy.

2. The Details of Completing Transcendental Idealism:

What was the concrete shape and structure of the completion of Transcendental Idealism?
In the theoretical philosophy, Kant for example takes it for granted that the forms of thought may be applicable to the material elements (objectivity) of knowledge, and yet he did not work out and clarify the ground for its possibility, namely how our understanding which is totally different from its object can be applied to the object so that they would produce an a priori synthetic knowledge. For example, Kant attempted to deduce the category of substance or that of causality from the form of judgment, but according to Fichte, this actually means that the category of substance or the category of causality was not founded on the nature of intelligence, but was obtained from the experience to which Formal Logic applies. In order to authentically understand why reason must think in accordance with the categories, Fichte maintains, those Tathandlungen (the pure activities of the Self or I), i.e., the forms of our thought, must be demonstrated indeed to be the rules of our thinking. In other words, these categories are to be demonstrated as the condition of the possibility of self consciousness. Not only did Kant fail to do this, but he also failed to justify even space and time as forms of sensibility.
Even if Kant might have done this, so argues Fichte, then Kant was not able to provide the ground for and elucidate the origin of the material elements of our knowledge. Unless, before the eye of the philosophizing spirit, objectivity as a whole is "produced," so argues Fichte, dogmatism can not be completely eliminated. We cannot leave the thing in itself as something totally independent of our thought. According to Fichte, the thing in itself is nothing but that which the subjectivity has to justify and "produce!"
Just as the relation between form and matter of our knowledge has been "modified", the opposition and differentiation between understanding and senses are to be abolished and to be reduced to a common principle, namely subjectivity. Sensitivity is to be understood now also by the Spontaneity of subjectivity that the subjectivity determines itself.
In his practical philosophy (ethics), so insists Fichte, Kant left many questions unsolved. For example, according to Fichte, the so-called "categorical imperative" is not the ultimate. Therefore, the categorical imperative also to be philosophically justified. The categorical imperative is in itself the principle, but is to be deducible from the other, more fundamental principle. The authentic principle is the imperative of the absolute independence of reason (absolute Selbstständigkeit der Vernunft).
Furthermore, in order to obtain a substantial moral theory and not just a formal ethics, the relationship between moral consciousness and natural impulses must be well elaborated and elucidated.
Thirdly, the relationship between the theoretical philosophy and the practical philosophy in Kant's thought is untouched by Kant and thus it remained obscure.
What Kant did was that he only distinguished them. This dualism must be overcome.

3. Choice of Philosophical Standpoint (Idealism or Dogmatism?)

Fichte has his own new innovative conception of Idealism apart from Kantian philosophy. According to Fichte, only two logically consistent systems of philosophy are possible, the one is dogmatism or realism and the other is idealism. Namely, the former (dogmatism) attempts to deduce ideas from things, while the former (idealism) endeavors to produce being from thought. Dogmatism is in error regarding its principle (because no one can produce thought from being!). If dogmatism were maintained consistently throughout, then it turns out to be like the system of Spinoza in the sense of materialism.
In this position they cannot escape from causal determinism (and there is no space for freedom of humanity). For everything is of nature or a product of nature and is governed by mechanistic causality. Therefore, dogmatism views spirit as an epiphenomenon of natural process and denies the human spirit the metaphysical and moral autonomy and its immateriality and thus the dogmatism fails to recognize freedom. In reality, thought cannot be produced or deduced from matter, therefore materialism or dogmatism must be erroneous in principle. In other words, being comes from the representation (the idea) while no representation comes from being.
However, Fichte maintains that being can be deduced from the representation, as consciousness (Bewußtsein) is also being (Sein) and yet consciousness is more than being. For consciousness (Bewußtsein) is ein bewußtes Sein (a conscious being). Thus it is obvious, according to Fichte, that consciousness (Bewußtsein) not only contains being but knowledge of being as its moments as well. Idealism can explain dogmatism, but the latter (dogmatism) can not explain the former (idealism). The greatest error of dogmatism is dealing with the empty concepts above and beyond consciousness or self. The concept is empty when it lacks intuitive givenness, but according to Kant, there cannot be intellectual intuition in epistemology (Kant talks about intellectual intuition in Critique of Judgement). Fichte went far beyond Kant's assertion and contended that there is intellectual intuition which Kant failed to recognize in the human mind. The most pregnant sense of intuition is intellectual intuition which is intuition of the existing self to immediately grasp its own self. (Intuition is a way of cognition in which the object (that which is to be known) is known to the subject (the knower) immediately, I.e., without any mediation.)
Philosophy may be able to abstract and must abstract what is given. Thus philosophy must always behold its object at a higher view-point. However, the correct abstraction is to separate those which appear as a synthesis in our experience. It analyses our experiential consciousness because we must re-construct our experiential consciousness out of its essential elements and it produces the experiential consciousness right "in front of our own eyes." In other words, the correct abstraction is no other than the actual history of our experiential consciousness. This abstraction with the aim of genetic observation of the self does not go beyond experience, but penetrates into the depth of experience. This analysis of abstraction of experience in philosophy is, therefore, not transcendent, but transcendental, precisely because of the above. Such an abstraction, maintaining the immediate connection with intuition, provides an actual philosophy (die wirkliche Philosophie) in contrast with various formal philosophical systems. By means of remaining within consciousness, i.e., within the self, the significance and advantage of idealism consists in being capable of the correct abstraction without being involved in those empty concepts. This is the theoretical strength of idealism.

The law of morality asserts, "Thou shall be independent." (Du sollst selbstständig sein!) In other words, independence may be understood as freedom and autonomy of the human-being. Therefore, "You ought to be free and autonomous." As Kant clearly pointed out, if we as humans ought to be independent, we must be capable of being independent. The ought (Sollen) of being independent presupposes its can (Können). However, if we are of matter or deducible from matter, we are not able to be independent. Therefore, idealism, seen from the practical point of view, is the only philosophical point of view which is consistent with the moral concept of "ought." From a different way of looking at this, we may say that one who adheres to realism has not yet elevated himself/herself to being free and autonomous, thus to the domain of morality. For in order to be able to know that you are free, you must first of all liberate yourself. Idealism can demonstrate that the idealist is free, and yet to be an idealist it is necessary to liberate oneself as an autonomous agent, to thereby be able to fulfill the moral obligation. "Those who fulfill the moral obligation, and who are free, are those who choose idealism for the sake of freedom. What kind of philosophical position one chooses depends upon what kind of human-being she/he is."

Was für eine Philosophie man wähle, hängt sonach davon ab, was man für ein Mensch ist: Denn ein philosophisches System ist nicht ein todter Hausrath, den man ablegn oder annehmen könnte, wie es uns beliebte, sondern es ist beseelt durch die Seele des Menschen, der es hat. ‹Die erste Einleitung zirr Wissenschaftslehre [What kind of philosophy one chooses depends upon what kind of human-being one is. For a philosophical system is not a "dead" utensil which one could reject or accept as if it were arbitrary. On the contrary, the philosophical system is enlivened by the human soul that one possesses.]

On the other hand, according to Fichte, it does not repudiate idealism even if the law of morality demands the reality of the external world and that of other spirits, for idealism does not deny realism, namely the reality of everyday life. Idealism explains realism not as the ultimate point of view, but as the necessary viewpoint for our mundane way of life. Contrary to idealism, dogmatism is an attempt to explain the philosophical viewpoint from the vulgar point of view. Idealism is related to the philosophical explanation while the mundane consciousness is to dogmatic realism.
Fichte contends idealism is the only defensible, satisfactory viewpoint both theoretically and practically. Just like the natural impulse and the moral volition in human action, both realism and idealism are rooted in Reason. Idealism is the ultimate philosophical position because idealism is able to explain realism, while dogmatism cannot explain idealism.

4. What is the Science of Knowledge or die Wissenschaftslehre?

What is the nature and aim of the Fichtean Wissenschaftslehre (the doctrine of science = Science of Knowledge)? Die Wissenschaftslehre is the authentically radicalized idealism and elevates Kant's philosophy to the level in which the science of knowledge becomes an evident and intuitive science as the philosophical basis for the transcendental philosophy. This evident science (Fichte's philosophy) seeks to eliminate the dualism of intuition and thinking on the one hand and dualism of knowledge and volition on the other so as to attain absolute monism. In other words, this evident science demonstrates both these dichotomies as deducible from one and the only one principle, namely the activity of the sole ego (die Tathandlung des einzigen Ichs).

Why this evident science is called die Wissenschaftslehre is because it adequately and ultimately answers the question,

How is knowledge (Wissen) possible?
How is experience possible?

This is not the science about "fact", but the science about "knowledge" (die Wissenschaft von Wissen). In Kant's terms, it is the transcendental philosophy. This "knowledge" does not include our everyday practical knowledge and common-sense knowledge, but exclusively deals with the knowledge of sciences. To Fichte, this knowledge (Wissen) includes not only common sense but the totality of all the scientific disciplines. Therefore, die Wissenschaftslehre is to intuitively elucidate the structure of our consciousness functioning both in our mundane life and in all the special sciences. Die Wissenschaftslehre deals with the necessary ideas or the necessary actions, while the other special sciences deal with arbitrary (willkürlich) ideas or action (=behavior). For example, we can arbitrarily represent the idea of triangle or circle, while the idea of space for instance is necessary and cannot be arbitrarily abstracted. Die Wissenschaftslehre intends to deal with those necessary ideas (=representations).

Why did intellect come to term with sensitivity?
Why did intellect come to intuitively know space and time?
Why did intellect create such specific categories as substance and causality?

Kant adequately described the activities of the intuitive spirit and the speculative spirit, but as answers to the above questions, these activities are to be demonstrated as necessary and to be deducted from the basis of all consciousness, i.e., from the Tathandlung des absoluten Ichs. Die Tathandlung is contrasted to die Tatsache. Die Tathandlung is also called pure activity. The self is according to Fichte nothing but this pure activity of the self or ego. Die Wissenschaftslehre deduces everything systematically from the self as the pure activity (Tathandlung). the highest pure activity of the self forms three principles.
The Tasks of The Wissenschaftslehre (Science of Knowledge)
(1) the Tasks Kant had left unsolved (viewed from Fichte's viewpoint)
a) Radicalization of idealism
b) Systematization of idealism
both of which is supposed to lead to the completion of idealism

(2) The Details for The Completion of Philosophy of Idealism
Theoretical Philosophy
Form and Matter
The forms of thought (=Categories)
The forms of sensibility (Space and Time)
That which is affected through senses by Thing itself
Understanding and Sensibility

Practical Philosophy
The origin of the affirmative proposition
The relation between the Moral Consciousness and
the Natural Impulse

The Relationship Between theoretical and Practical Philosophy

(3) Choice of Philosophical Stand.
The Theoretical Justification
The Practical Justification

The Choice of either
Realism (Dogmatism)

(4) Nature of Wissenschaftslehre

II. The Three Basic Principles (Die drei Grundsätze)
The highest forms of Tathandlung take three distinct Principles. They are led by the need for self reflection. In the case of thinking, What does the self necessarily do? It is the fact that in case of thinking (being conscious of) anything, the I inevitably thinks (is conscious) of one's own self and that we are not able to abstract this I or self from this activity at all.
That, I think, means either that the I affirms my self or that the I posits my self. Here it becomes obvious that thereby the affirming I and the affirmed I become apart, the positing I and the posited I, the thinking I and the I being thought of, distinguish themselves within the I or ego. This means further that the I or self is the subject and the object at the same time. The nature of self consciousness consists in the very identity of the representing and the represented. Such pure I or self is not a fact (Tatsache), but an activity (Tathandlung). this activity (Tathandlung) takes place unconsciously and it is by intellectual intuition that the self is aware of this unconscious pure activity. This is the meaning of the First principle. The First Principle says,

Das Ich setze ursprünglich schlechthin sein eigenes Sein.‹Grundlage, p. 98

[The self primarily and directly posits its own being.]

That is, "the I or self (=ego) posits itself"(Das Ich setzt sich selbst. [p. 96]), or more simply, "I am", (Ich bin. [p. 96]). The nature of the self is no other than its activity that the I posits itself as my own being. The Cartesian "I think, therefore I am", as well as Kant's "synthesis" are this Tathandlung itself. Logically speaking, from this Tathandlung, the principle of identity ( A=A ) is deduced. In the categories, Kant's category of reality may be deduced from this.
This First Principle is that by which the I thinks of itself, and yet in the fact of our experiential consciousness, together with the I's positing itself, something other, "something opposite and foreign" comes to appear. Needless to say, what is something opposite is no other than opposite to the I itself (for nothing else does exist).
Thus The Second Principle states:

"Against the I the non-I posits itself".

From this Second Principle, the logical Principle of Contradiction is deduced and the Category of Negation is deducible.
The First Principle and The Second Principle are to be reconciled. Since both the I and the non-I are opposing each other within the (original) I itself, they are to be posited as mutually limiting. In other words, they are to be posited as mutually annulling its own portion, i.e., they are to be posited as being divisible (teilbar).
Thus The Third Principle states:

"Ich setze im Ich dem teilbaren Ich ein teilbares Nicht-Ich entgegen." [p. 110].

From this Third Principle the logical Principle of Reason (der Satz des Grundes), for that principle contains the reason for the synthesis and unity of the I and the non-I. The Category of Determination (die Kategorie der Bestimmung) is deducible from this.
Simply, the I (without its opposing non-I) as such and the non-I (without its opposing I) as such alone are indeterminate, infinite. By the Third Principle, they are now determined as the divisible I and the divisible non-I and being posited as opposite, they are now mutually determinant and in consequence determined, definite. This is what Kant called the Category of Limitation.
Those three Categories which are deducible from the three Principles belong to The Categories of Quality (Reality, Negation and Limitation).
The I that is the object of the intellectual intuition is the I which serves as the Ground of all beings, and is by no means an individual I.
It is the I-ness, the Spirituality as such (die Geistigkeit überhaupt), the Eternal Reason itself (die ewige Vernunft).
This I as the Eternal Reason is both common to and the one with every I that is. It appears in every thought and exists in it as its ground. To this absolute I an individual I is merely its accident (die Akzidenz), its means or its particular expression. this absolute I is pure activity and not a Substance. The pure I could not be conceived as an entity existing before this pure activity. Being is the accident and the result of this pure activity. The pure activity of the I is primary, the substance is secondary. In Goethe's Faust in Studienzimmer Szene (1224-1237), Faust opened with the beginning of the Gospel according to St. John in the New Testament, and wondered about the proper translation for the Greek word, "Logos" in the context of "In the beginning was the Word (Am Anfang war das Wort [Luther's translation]). Instead of "the Word", Faust tried, "Meaning" (Sinn), then "Power" (Kraft), then finally he settled on the word "Action" (Tat). According to Fichte, this Tat is no other than his Tathandlung, the pure activity of the absolute I.
The three activities expressed by the above Three Principles are isolated, mutually independent activities of the I. To the contrary, these three positings (Setzungen) are but one and encompassing, total activity. It is the beginning of the total system of the unconscious various activities and the inquiry into these various activities is the task of the Wissenschaftslehre.
In the Wissenschaftslehre the thesis (=the position of the I), the antithesis (=the position of the non-I), and the synthesis (=the position of the I and the non-I in mutual limitation) repeatedly appear to elucidate Fichte's thought and this is the very forerunner of Hegel's dialectic. This may trace back to what Kant called "eine artige Betrachtung", his Categories. If we may go further back, we may find it in Jacob Boehme.
Within The Third Principle, there are two propositions included:

1) Das Ich setzt sich als bestimmt durch das Nicht-Ich.
(The I posits itself as determined by the non-I.)
2) Das Ich setzt sich als bestimmend das Nicht-Ich.
(The I posits itself as determining the non-I.)

1) deals with the cognitive activity of the self, while 2) deals with the practical activity of the self.

III. The theoretical I (the I as cognitive faculty)

One of the two propositions,"the I posits itself as being determined by the non-I" which are
contained in the Third principle purports the cognitive act of the self. Furthermore, this proposition contains two more propositions:

1) "The non-I determines the I." In other words,, the I is "affected" by the other, namely "The I suffers(leidet=is acted upon) by the non-I".
2) "The I posits itself", i.e., "the I determines itself", that is,
the I posits by itself its own determination. Namely,
"The I is active (=tätig)".

These two propositions are to be reconciled in such a way that a portion of the I is viewed as determining, while the other portion of the I is viewed as being determined. Needless to say, this is based on the Third Principle that reveals that the I is divisible(=teilbar). This "being divisible" means "being capable of quantity." That one portion of the I is viewed as determining, while the other portion of the I is viewed as being determined is the same as the I posits in itself the negation in as much as posits in the non-I the reality, i.e., the same reality that is negated in the I is to be posited in the non-I. from here the Category of Quantity is derived. Quantitatively viewed, the being acted upon (=leiden) of the I is no other than the decrease of being active of the I. Being acted upon (=leiden) is a certain quantity of being active, i.e., that of the I. Unless the I is active, it is acted upon, or unless the I is active, the non-I is active. In short, the non-I is after all a portion of the I itself. Fichte tried to demonstrate this relationship of the I and the non-I by means of the analogy between the light (das Licht) and the darkness (das Finsternis), Reality, Negation and Limitation. Thus from the Limitation as one of the Categories - the Third Category of Quality, the Categories of Relation are to be derived.
In the propositions, "The I is acted upon by the non-I" and "The I is active", the relationship between the I and the non-I are carefully examined, then the Three Categories of Relation, namely, 1. Mutual Determination, 2. Causality, 3. Substance,

1. The Category of Mutual Determination (Wechselwirkung):
The Reality, once negated in the I, is posited with equal quantity.

As determinatio est negatio is said, between the I and the non-I the determination is mutually done by negation.

2. The Category of Causality:
The cause of the I's being-acted-upon is the non-I, and as its result,
the I's being-acted-upon (suffering=leiden) is produced.
Thus the Category of Causality is derived.

3. The Category of Substance:
The being-acted upon (leiden=suffering) of the I is the limitation of the I upon itself.
Since the I's being-acted-upon (suffering=leiden) is viewed as an accident at its very portion, the activity of the I is fundamentally the substance. Thus from this the Category of Substance is derived. So subsist the necessary relationships among the three Categories of Relation which are derivable therefrom.

Furthermore, these categories represent three philosophical positions:

1) In view of Causality,
Dogmatic Realism, e.g., Spinoza's philosophy.

2) In view of Substance,
Dogmatic Idealism, e.g., Berkeley's philosophy.
3) In view of Mutual Determination,
Critical Idealism, Kant-Fichte's philosophical system.

That the I possesses Substantiality, while the non-I possesses Causality, can be viewed also as these two functions contained the (absolute) I, or this can further construed as the two, opposite directional powers. This power as a whole is the striving to infinity and it is also said to be the limitless productive power (Produktionsvermögen).
Compare with Kant's distinction of Imagination;

Die Einbildungskraft

Its effects: Schemata
The Medium to mediate categories and perception between concepts and intuition

The effect of the productive imagination is the object as such. The totality of the (external) reality is produced by this imagination.

Ohne diese wunderbare Vermögen läßt sich gar nichts im menschlichen Geiste erklären, und auf welches dürfte sich gar leicht der ganze Mechanismus des menschlichen Geistes gründen [Grundlage, p. 208]).

The production of the productive imagination is prior to our conscious activities and unconscious activities. Therefore, we believe that objectivity (the external reality) appears to be discovered. The various representations are the various steps of the unconscious productivity. Thus, from the pure activity of the I, namely from the productive imagination, the fact of consciousness in general must be explained. This Fichte called "die Deduktion der Vorstellung".

The Deduction of Representations

1) Feeling (Gefühl) or sensation (Empfindung)

i.e., "In-sich Findung", to find in itself (the I itself). However, The I or self finds (this) as something other and yet finds in itself. In sensation no distinction between the being conscious and the being-conscious-of.

2) Intuition (die Anschauung).
When the I reflects upon its own sensation, and posits that which limits the I and looks at it, this act is Intuition (Anschauung), in which the non-I is intuited, and what is intuited appears as if it were the product of the non-I.

3) The reproductive imagination (= das Nach-bilden).
Taking into itself the intuition the I reproduces(nach-bilden) the intuition. its product is a "picture" (das Bild), i.e., das Nachbild to be exact. While this Nachbild is our representation, its original (das Vorbild) is the thing in itself. Here the thing in itself (das wirkende Ding) and the picture (das Bild) are distinguished. Thus the I reproduces (pictures) the Intuition (its own product as the non-I) in itself. In other words, the I consciously reproduces what the I unconsciously produced. Thus, while the productive imagination produces reality, the reproductive imagination produces representation.

4) Understanding (der Verstand):
According to Fichte what produces the Categories is also imagination. Understanding simply makes the categories applicable to the laws. Fichte even argues that Hume was right in maintaining that Causality is a product of imagination, although Hume erred in failing to recognize the objective validity of causality.
Kant viewed the Categories as the primary forms of thinking, i.e., that the Categories originate from Understanding, and he had to elaborate in the Schematism the Categories in conjunction with productive imagination in order to make the objective application of the Categories possible. In contrast, according to Fichte, Kant was right in the lawfulness of the Categories, and yet erred regarding the origin of the Categories. The Categories are not the products of Understanding, but they arise at the same time as objectivity, (external) reality and solely on the basis of the productive imagination.
Space and Time, too, according to Fichte, have their origin in imagination. While Kant discovered Space and Time as the a priori forms of intuition, Fichte attempts to deduce a priori Space and time. As a result, they are demonstrated as existing in the I.
Understanding solidifies the fluid intuition by means of concepts so that by understanding, the product of imagination becomes objectivity, the (external) reality.

5) Judgment (die Urtielskraft):
Judgment is the free ability (das freie Vermögen) of reflection. It is the ability whether or not to direct reflection to a certain object. It freely abstracts a certain object of understanding and it is an ability to, at will, connect or separate certain characteristics (Merkmale).

6) Reason (die Vernunft):
While understanding is the ability to abstract a certain objectivity, Reason is the ability to abstract objectivity itself as a whole. Reason is conscious of itself as the ability of abstraction which does not direct itself to a particular object. it is the I in its absolute, pure subjectivity. The significance and ability of Reason is Self-Consciousness. The freer Reason becomes from objectivity, the closer the empirical I comes to pure self consciousness.

IV. The Practical I (Das Praktische Ich)

The deduction of the various representations reveals the various steps of our cognition:
The Sensory Intuition
Reproductive Imagination

The Spiritual Judgment

In the section on theoretical philosophy, Fichte did not explain why the I, hindering itself from going to the infinity of its own self, goes back to its self. In order that the consciousness or cognition is formed, it was necessary to "give" or "produce" within itself the first limitation or hindrance (Anstoß). By so doing, Sensation was produced, and on that basis Understanding through reflections, the objective world was "built" or produced. Unless, therefore, the I limits its own infinite activity, there would be no representation, nor objectivity itself.
Why does consciousness, representation, or the world exist at all? "Where did the primordial non-I come from? Where did the hindrance (Anstoß) come from which hinders the I from going to infinity and has it return to the I itself?"
As long as we remain within the domain of the theoretical I, we are not able to answer these questions. For the theoretical I itself was born from encountering that hindrance. This hindrance (der Anstoß) has to be deduced, which is only possible in the domain of the practical I. The Primacy of the Practical Reason that Kant emphasized will be able to do so.
To become the theoretical I by limiting itself is, for the I, to become the practical I. There are the ability of representation and the world of representation in the theoretical world because we, as the practical Is, provide ourselves with the possibility of fulfilling the moral obligation. Why we are Intellect is because we may be able to be Will. We exist and, in consequence, recognize (the world), because we must act, and morally act. (To will and to act, it is necessary to have its object to "act upon.") To act means to give the form to its matter, to "process" and modify objectivity. The objective world is but the means to accomplish our moral end. Thus, "the objective world is the sensory matter for our moral obligation." It is not possible for the practical I to act, unless there is the objective world to act on. In other words, unless there is a hindrance, unless there is the non I, the practical I cannot act. Thus, the hindrance (der Anstoß) is deduced.
Moral obligation is the one and the only one in-itself (das An sich) in the phenomenal world (the moral ought is the form!). That is to say, genuine reality in the phenomenal world is this moral ought. "The so called Being in itself (das An sich) of the thing is precisely that which we produce (as its form) from that very thing. Objectivity exists in order to be gradually abandoned, because objectivity exists to be processed and modified so that the activity of the I may reveal itself.
By means of the same explanation as the necessity of the external world becomes clear, it becomes apparent that the infinite I diverges itself into many empirical Is' or into individuals. By the same token we now understand why the infinite I does not immediately actualize its own plan, but has the finite spirits do so as its means. In his later works, Fichte called this infinite I "the universal Life" (das allgemeine Leben) or "the Godhead" (die Gottheit). The moral act can only be performed by the finite, individual I. Without hindrance, i.e., resistance, there is no act, without war (=moral conflict), there is no morality, according to Fichte. Needless to say, this individuality must be overcome (and made into an infinite I) by the achievement of the moral act, for the very reason of which there must exist the individual.

Morality is to overcome both the inner and outer nature.

Now, what does Fichte mean by "nature?" In the practical I, there are to be clarified the various steps of impulse or drive (Trieb). This Trieb (impulse) is the inner nature. The practical I constitutes the system of necessary impulses just like the theoretical I did. According to Johann Fichte, the I is a infinite strife or endeavor (of activity) = ein unendliches Streben. When the endeavor is posited by the I itself as the inner, subjective one, it is called drive or impulse (der Trieb). When this Trieb arises solely out of the I, then this drive is related to and directed toward the I alone. However, the nature of the I consists in reflection, thus the I's drive is the drive for reflection. The reflection needs its object and its drive is the drive for representation (der Vorstellungstrieb), whose activity does posit the object. That is, therefore, the drive to produce reality (der Produktionstrieb).
This drive for reality is called yearning (das Sehnen), it is thus, further, the drive for satisfaction (der Befriedigungstrieb). This is accomplished when there exists a harmony between the drive and the act. When not matched, dissatisfaction is felt. Sometimes the act to satisfy a particular drive itself a drive. That is the endeavor which discovers satisfaction in its own act itself and not by any consequence. This absolute drive (der absolute Trieb) is der Trieb um des Triebes willen, i.e., das Streben um des Streben willen. Fichte called this den sittlichen Trieb (=the moral drive or impulse). This is in itself the practical I itself. thus various drives are derived. Der kategorische Imperativ means the absolute Law for Law's sake, "Du sollst...!"

das Ich=das Streben
(I = striving)

der Trieb

(instinctive drive, which is the inner nature)

der Reflexionstrieb = der Vorstellungstrieb
(reflective drive = the drive for representation)

der Produktionstrieb
(das Sehnen)
(desire or productive drive, whose object is the outer nature)

(The drive for satisfaction)

der Trieb nach Harmonie zwischen Trieb und Handlung
(the drive for harmony between drive and action)
der absolute Trieb
der Trieb um des Triebes willen
(das Streben um des Strebens willen)

(The absolute drive or the drive for the sake of drive)

der sittlicher Trieb
(the ethical drive)

das praktische Ich
(the practical I)
The primordial I is the I that is striving for infinity. Thus, the practical I is the bridge, the mediator, between the theoretical I and the absolute, infinite I. That is, the I who is in itself not infinite is striving for becoming infinite.
Among obligations, there are universal obligations and mediated particular obligations.

unconditional or universal obligation
mediated particular obligation

By starting with the immediate, highest principle, the task of the Science of Knowledge is to overcome the dualism between the intuition and thinking, that between cognition and will. Thus, once it is accomplished, the Science of Knowledge is completed.

2. Morallity (Sittlichkeit) And Jurisprudence
In Fichte's philosophy, the Non-I possesses a negative significance in that it's role is to disturb or hinder the activities of the I. In Fichte's system, in this sense, the Non-I or Nature cannot become a philosophical theme as such.
Therefore, there is no Philosophy of Nature in Fichte's philosophy.
The areas to which the principles of the Science of Knowledge is applicable are such spiritual aspects of reality as Morality, Jurisprudence, History and Religion.

The principle of morality demands to govern the sensory impulse by means of the pure impulse, the absolute impulse (=the impulse for the impulse sake, conf. above). Our sensory impulse, being directed to the fulfillment of pleasure and leisure, makes us dependent on the object (= the external world, the outer nature, = the Non-I).
Contrary to this, the pure or absolute moral impulse, being directed to the self and the pure self satisfaction, pursues the industriousness labor and independence (of the outer nature). In our moral pursuit, the pleasure is not allowed to be the object of our behavior. Morality is the activity for the sake of activity. Just as Kant held, Fichte, too, maintained that, should our will or action produce pleasure by chance, such a will or action cannot be called "moral." Our moral will or act must be pursued only for the sake of the moral ought.

Das radikale Böse ist die Trägheit!

Die Trägheit (laziness) is the volition which does not heighten itself to the clear consciousness of moral duty and freedom beyond the natural impulse of self preservation. For a truly moral agent, there is no such a thing as leisure (Trägheit) or rest. An moral action will incessantly arouse the next. The moral imperative would be:

Be Independent, behave autonomously and liberate oneself: Make sure that one ought to make each action in the series of actions such that such a series of action will ultimately result in the self's becoming autonomous.

Fichte's view of morality is well represented by Goethe's words in Faust,

"Werd' ich beruhigt je mich auf ein Faulbett legen, So sei es gleich um ich getran!"
[If I would soothingly lie on the easy chair, I would have finished!] (Faust I. 1692-1693)

The above is the formal, universal moral principle.
Now, needless to say, each individual moral person is given a task peculiar to oneself by the world order. Each individual person ought to do what only that individual person can and ought to do.

Do what is one's own moral task, one's own ethical share!

Going beyond the formality and abstractness of Kantian moral imperative, Fichte attempted to provide a more concrete imperative peculiar to each individual moral person by establishing the principle of the individual's self independence.
In order for the self of a concrete moral individual person to attain the freedom, there are 4 stages:

1) At the beginning, freedom exists only in the consciousness of natural impulse. Namely, freedom comes into being, only if one reflects on various possible alternatives of action, this freedom is formal.
2) There is a condition (=freedom) in which one is able to escape from the natural impulse by means of the maxim (self-given law) of one's own happiness.
3) In this higher stage, one becomes excited and in a sense blind such that one is to heroically sacrifice oneself. It is the condition in which one will act selflessly, i.e., nobly, out of simple inclination.
4) In this stage of the genuine morality, paying an attention to the moral principles, one will act out the moral duty out of the duty itself, and must steadily be conscious of morality.

In order for a human being to free oneself from the laziness (Trägheit) as the original sinn (das radikale Böse), one needs to have an ideal example of moral action. The ideal form of freedom by a genius individual is necessary to be shown to us.
Such an ideal example may be found among the founders of the great religions (e.g., Christ or Buddha). The moral conviction of a religious founder is widely circulated by the church, but the dogmas of the church are to be viewed rather as symbols and not as the doctrines themselves. Therefore, the church is a kind of convenient and temporal institution for morality and die Notkriche (this temporally necessary church) should be taken over by the Church of Reason (die Vernunftkirche) through our moral philosophy.
Fichte established a system of duties or moral obligations.
The end of the moral principles is Reason as such, whereby the purpose of the moral principles is to have the state or government of Reason appear in the midst of the world of sensibility. The means to fulfill this end is the particular, finite self or the empirical individual person. The realization of this purpose depends upon this means' having the right constitution. Thus, the moral duties must be related both to the end and to the means.

The moral duties
I) conditioned or mediated duties (the means)
I-i) universal moral duties
I-ii) particular moral duties
II) unconditional or immediate duties (the purpose)
II-iii) universal moral duties
II-iv) particular moral duties

I-i) The universal, conditional moral duty:
This is each individual's moral duty and yet it must be universal.

In order for an individual to live and work as the means for the moral principles, the self preservation of the individual is necessary as a moral duty.
There is a great difference between the self preservation as the right and the self preservation as the moral duty. The former consists in the self preservation to attain the consequences or pleasures of an action, while the latter consists in the self preservation in order to morally act in accordance with the principles of morality, utterly independent of the consequences or pleasures of an action.
Therefore, suicide, for example, is against the principles of morality. (System der Sittenlehre, S. 263-8) According to Fichte, suicide is regarded as unethical (not from the religious reason).

I-ii) The particular, conditional moral duties:
These are moral duties related to each particular individual. In order to act for the end of Reason, one ought not to simply act, but act systematically (plannmässig), i.e., one ought to choose the conditions appropriate to oneself ( in accordance with one's social standing, e.g. one's vocation and position, circumstances and class), thus in the moral world, it is one's particular moral duty to choose one's own standing and vocation, and yet it ought not be chosen by others or by one's inclination, but by oneself out of pure duties.

II-iii) The universal, unconditional moral duty:
The moral duties which are immediately related to the ultimate, moral ends. They are universal. In the world of sensibility, Reason must govern each individual individually. They are the duties to others as the humans. Thus,

Behandele den anderen seiner moralischen Bestimmung gemäß!

In other words, this means, "One must not harm others!" For the primary condition of the morality is freedom, so to treat others as moral entities means to treat them as free beings. In order to treat others as moral agents, one must consider to not harm others' lives and properties. This is the universal, unconditional moral duty.

Do not harm others' lives and properties!

II-iv) The particular, unconditional moral duties:
They are the moral duties in regards to the ultimate end and yet they are particular. They are particular, as long as they are concerned about the social standing, vocation. Fichte discussed in detail about the duty of the married couple, between parents and children, that of the scientist (=the service to the science with love of truth, i.e., honesty), of the priest (=the ideal example of moral actions), of the artist (= not to be an artist, unless you are a genius, for no moral imperative can command the aesthetic feeling) and of the bureaucrat (=justice). Fichte distinguished among the vocations, the high and the low vocations, namely

Regarding his philosophy of law, Fichte held the law of nature quite independent of morality (Kant held the same position, although Fichte's Grundlage des Naturrechts (The Foundations of the Natural Law - 1798) appeared before Kant's book on the natural law).
According to Fichte, the jurisprudence cannot be deduced from moral laws. The moral law can sanction a certain concept of jurisprudence and yet it cannot produce it.
A law is valid quite independently of morality. While a law allows to exercise a certain right under any circumstance, morality sometimes forbids it. While the moral law under any circumstances requires good will and would not allow anything else than posited by good will, the law is valid without good will. Jurisprudence is concerned with expression of freedom in the sensible world. That is, such an expression is an external behavior, to which the law is related.
The law can coerce, while morality cannot. The law is concerned about the behavior in the world of senses and is not concerned with "intention" (die Gesinnung) which constitutes the core of morality (and not the consequence or pleasure that the action will bring about).
For philosophical justification, it is necessary to deduce the law as the necessary behavior of the I, namely as the condition for the self-consciousness. According to Fichte, the I must posit itself as a finite Individual, i.e., must posit itself as being related to the finite individuals. By so doing, as a finite individual, I must set itself in legal relation to the other rational, individual beings. In other words, I as finite, particular individuals, a finite I and the other finite Is recognize each other's freedom and accordingly act responsibly.
A finite rational being cannot posit itself, unless it acknowledges its own freedom in the external sensory world. In order to acknowledge one's own free activities, it is necessary to further recognize other finite rational beings and other's free activities as well: That means, a finite rational I is in legal relation to the other rational Is.
Secondly, it means further that a finite I recognizes its material corporeal body to itself and acknowledges itself as being under the influence of the others.
The community of the finite free individual beings is the condition for the individual self consciousness, and yet in order that such a community of the free agents may be possible, the principle of juris.