1. The Kantian Opening and the Pantheism Controversy (1781–1787)

The movement begins with an epistemological crisis: if reason is autonomous, does it lead to freedom or a cold, Spinozistic fatalism?

• 1781: The First Critique. Kant’s Kritik der reinen Vernunft introduces the transcendental deduction but leaves the "Thing-in-itself" as an unknowable substratum.

• 1785: The Pantheismusstreit. Jacobi reveals that Lessing was a "Spinozist." This creates a panic: Reason seems to lead to Atheism and Fatalism. The Idealists' mission becomes finding a "Spinozism of Freedom."

• The Personal Relation (Kant): Kant remained an "island." He famously issued a public "Declaration" in 1799 against Fichte, stating that the Wissenschaftslehre was a totally different system and that "God protect us from our friends." He never met the younger generation.

2. Reinhold and the Drive for Systematicity (1789–1792)

• Karl Leonhard Reinhold, a former Jesuit, "sold" Kant to the public. He argued Kant lacked a single "First Principle."

• His Idea: The "Principle of Consciousness." He attempted to unify subject and object through the act of representation (Vorstellung).

• He failed because his representation still required an external object, thus re-importing the "Thing-in-itself" through a backdoor. 

3. The Skeptical Catalyst: Schulze and the Young Fichte (1792–1794)

• 1792: Schulze’s Aenesidemus. An anonymous attack on Reinhold. It argues that if causality is only a mental category, we cannot use it to say a "thing" causes our sensations.

• The Collision: J.G. Fichte reviews the book. This is his turning point. He realizes the "Thing-in-itself" must be abolished. The "I" must posit itself and its own limits.

4. The Tübingen Triumvirate: Hegel, Schelling, and Hölderlin (1790–1797)

While Fichte was in Jena, a different revolution was brewing in the Stift (seminary) at Tübingen.

• The Roommates: Hegel, Schelling, and Hölderlin shared Room 4. They were bonded by a shared anger with the "orthodoxy" of the seminary and a passion for the French Revolution.

• The Älteste Systemprogramm des deutschen Idealismus (1796):

  • It is written in Hegel's handwriting, but the poetic-philosophical impulse is largely attributed to Hölderlin.

  • It demands a "Monotheism of Reason" and a "Polytheism of Imagination." It calls for the abolition of the State (as a "mechanical" entity) and the creation of a "New Religion of the Idea" where philosophy becomes aesthetic.

  • Hölderlin’s Influence: In Urtheil und Seyn, Hölderlin argued that "Being" is prior to the "I-subject." This critique of Fichte deeply influenced Schelling's move toward Identity.

5. The Jena Symbiosis and the Great Fracture (1794–1801)

• Fichte & Schelling: Fichte arrives in Jena in 1794. The young Schelling (only 19) becomes his "apostle."

• The Split: By 1797, Schelling begins his Naturphilosophie. He views Nature as "unconscious Spirit" rather than Fichte's dead "Not-I." Fichte views this as a return to "dogmatic" Spinozism. Their letters become increasingly bitter until their final break in 1801.

• The Atheism Dispute (1799): Fichte is forced out of Jena. This creates a vacuum that Schelling fills, eventually inviting Hegel to join him.

6. Hegel’s "Junior Partnership" and the Betrayal (1801–1807)

• Hegel moves to Jena in 1801 to work with Schelling. At first, he is seen as a "Schellingian."

• The Tactical Shift: While Schelling focuses on the "Point of Indifference" (immediate intuition), Hegel develops Mediation (Vermittlung).

• 1807: Phänomenologie des Geistes. In the Preface, Hegel mocks Schelling’s Absolute as "the night in which all cows are black." Schelling, who had supported Hegel financially, views this as a public betrayal and a theft of his ideas.

7. Systematic Outcome: The "New" Enlightenment

The movement doesn't just end; it transforms into the foundational principles of modern rationality.

• Rationality of History: History is the "unfolding of Reason." Enlightenment moves from static "human nature" to dynamic "human development."

• Identity of Rational and Actual: The State and Law are the "externalization" of reason. To be enlightened is to recognize the rational core within the social world (Sittlichkeit).

• The Concept of Bildung: Enlightenment is redefined as the process of overcoming one's particularity to achieve universality.

• Institutionalized Reason: The move from "intuition" to "mediation" leads directly to the Humboldtian Research University—Enlightenment as a rigorous, collective labor.

8. Conclusion: The Completion of the Event

In Die 25 Jahre der Philosophie, Eckart Förster provides a specific "systematic reconstruction" of this outcome:

• The Unity of the Period: Förster argues that the years 1781–1806 constitute a single philosophical "event." It is the process by which philosophy becomes "Science" (Wissenschaft).

• The Spinozism of Freedom: The movement succeeds when Hegel manages to synthesize Spinoza’s "Substance" with Kant’s "Subject." The Absolute is finally understood not as a thing, but as Spirit (Geist).

• The Organ of Philosophy: Förster emphasizes that the end-point was the discovery of the Dialectic. Philosophy no longer needs an external "thing" to know; it knows itself through its own historical and logical self-mediation.

• The Transcendental as Historical: The ultimate conclusion is that the "Conditions for the possibility of experience" (Kant) are revealed by Hegel to be the "Conditions for the historical development of Spirit." 

Here is a short summary diagram for the movement: