Friedrich Heinrich Jacobi

German philosopher (1743–1819), the principal anti-rationalist opponent in Schelling's 1809 *Philosophical Investigations into the Essence of Human Freedom* and the initiator of the Pantheismusstreit (1785). Jacobi's claim that the only consistent rational theology is Spinozism, and Spinozism is fatalism forced late-18th-century German philosophy into a dilemma: either accept Spinoza (and lose freedom) or perform the salto mortale — a "mortal leap" out of reason into faith. Schelling's Freedom Essay attempts to escape this dilemma by reformulating reason itself: reason can include immanence-in-God without collapsing into Spinozist fatalism if the ground/existence distinction is in place. Two Jacobi texts are appended as Supplementary Texts to the Freedom Essay volume: the Spinoza Letters excerpts (the Pantheismusstreit-launching dialogue with Lessing and Mendelssohn) and "On Human Freedom" (1789, his most systematic statement). Schelling and Jacobi worked together at the Bavarian Academy of Sciences from 1806 (when Jacobi was made President), but their relationship became "increasingly strained, ending with the complete break of 1812 in the so-called third pantheism debate" (editors' note 21).

Key Points

  • Born 1743 in Düsseldorf, died 1819 in Munich. Wealthy merchant family; first publishing in the 1770s; novels Edward Allwill and Woldemar; philosophical writings including On the Doctrine of Spinoza in Letters to Mr. Moses Mendelssohn (1785), David Hume on Faith (1787), On Human Freedom (1789), On Divine Things and Their Revelation (1811, which prompted Schelling's polemical Memorial of 1812 marking the final break).
  • The Pantheismusstreit (Pantheism Controversy, 1785+): Jacobi's 1785 publication of Lessing's alleged Spinozist confession launched the most consequential philosophical controversy of late-18th-century Germany. Jacobi's central claim: "the determinist, if he wants to cut to the heart of the matter, has to become a fatalist."
  • The salto mortale: Jacobi's name for "the mortal leap" — the move from determinism to "intelligible, personal cause of the world." "From fatalism I conclude immediately against fatalism." Jacobi explicitly stages this in the Spinoza Letters dialogue: Lessing politely declines to imitate it.
  • "On Human Freedom" (1789): structured as a dual argument: Part I (propositions I–XXIII: man has no freedom — the deterministic argument); Part II (XXIV–LII: man has freedom — the leap-of-faith answer). The salto mortale operates between the two parts: argument cannot bridge them.
  • Schelling's positioning: the Freedom Essay is structurally a response to Jacobi. Schelling: yes, immanence-in-God; no, not fatalism (because Spinoza's error is the thing-construal, not immanence); yes, freedom and necessity are compatible (via the eternal-act and ground/existence distinction); no, no salto mortale needed.
  • President of the Bavarian Academy of Sciences (1806–1812): Schelling's institutional superior at Munich. The personal-philosophical relationship was initially cordial; their break (1812) came after Jacobi published On Divine Things and Their Revelation and Schelling responded with the polemical Memorial of Mr. Friedrich Heinrich Jacobi's Writing on the Divine Things etc. (the only other substantial work Schelling published after the Freedom Essay).
  • One of the few philosophers Schelling rivaled at the personal level: editors note (line 715) that Schelling became "one of Jacobi's most ferocious critics."

Details

The Spinoza Letters and the Pantheismusstreit

The 1785 publication: On the Doctrine of Spinoza in Letters to Mr. Moses Mendelssohn (Über die Lehre des Spinoza in Briefen an Herrn Moses Mendelssohn). Jacobi reports a 1780 conversation with Lessing (Lessing died later that year) in which Lessing confessed Spinozism: "I came to talk to you about my hen kai pan. There is no other philosophy than the philosophy of Spinoza."

The philosophical stakes are immediate: if Lessing — the paradigmatic Aufklärung rationalist — was Spinozist, then all late-Enlightenment rationalist theology is implicitly Spinozist, and the choice is Spinoza or salto mortale. Mendelssohn's Morning Hours (1785) tries to defend Lessing as a rationalist-not-Spinozist and to defend a "purified pantheism" compatible with theism; Jacobi rejects both moves. Kant takes neither side publicly but writes "What is Orientation in Thinking?" (1786) as a response.

The full Lessing-Jacobi dialogue is in the Supplementary Texts to the Freedom Essay (raw lines ~1013–1151). Key passages:

  • Lessing: "the orthodox concepts of the divinity are no longer for me." Hen kai pan — "I know nothing else."
  • Jacobi: "the determinist, if he wants to cut to the heart of the matter, has to become a fatalist" (line 1023).
  • Jacobi: "I extricate myself from the matter with a salto mortale" (line 1051).
  • Lessing on the salto mortale: politely declines, "is it not possible to do without the salto?"
  • Jacobi: "He who does not want to explain what is incomprehensible but rather wants to know only the border where it begins... reclaims the most space within himself for genuine human truth" (line 1133) — Jacobi's positive doctrine.
  • Lessing on substance and thought: "Thinking is not the source of substance, but rather substance is the source of thinking" (line 1097) — the Spinozist priority of being that anticipates Schelling's unvordenklich.

"On Human Freedom" (1789)

Jacobi's most systematic statement. The dual structure is itself the argument: Jacobi cannot show that man has freedom by reasoning from determinism's premises, so he must construct two parallel arguments. Part I (propositions I–XXIII) derives no-freedom from purely mechanistic premises (the rational being is mechanism all the way down; sense of right is mechanical inner-consistency of one basic drive). Part II (XXIV–LII) constructs freedom as undeniable as actuality even if its possibility is incognoscible.

Key propositions:

  • Prop. XXV (raw line 1213): "a merely mediated — that is, an entirely mechanical — ACTION must likewise be a non-thing." (Pure mediation cannot ground the existence of finite things; therefore "PURE self-activity must necessarily form the basis for mechanism everywhere.")
  • Prop. XXXII (raw line 1229): "freedom exists, according to its essence, in the independence of the WILL from DESIRE." Freedom is not free-choice-among-things-of-desire but the honor-principle (XXXV cites Stoics).
  • Prop. XLVI (raw line 1270): "the object of pure love is... the Theion in man" — the Stoic / Kabbalistic register of freedom as obedience to one's own nature.
  • Prop. XLVIII (raw line 1240): "every individual being... has a double direction" (sensory drive vs intellectual drive).
  • Prop. LII (closing): the practical realization of freedom requires the leap-of-faith into the "personal, intelligible cause of the world."

The salto mortale operates between Part I and Part II: there is no rational bridge from mechanism to self-activity; the move requires faith. This is structurally what Schelling's Freedom Essay is designed to reject: Schelling provides the system that includes what Jacobi can only reach by leap.

Schelling's contrast

Schelling's relation to Jacobi can be reconstructed from the Freedom Essay as follows:

Position Jacobi Schelling
Spinoza's immanence rejected (= fatalism) accepted (but Spinoza errs in thing-construal, not immanence)
Spinoza's hen kai pan "the only consistent rationalism" — therefore reject rationalism rescue hen kai pan via ground/existence distinction
Rationalism's limit reached at the salto mortale — leap out of reason reached at the Ungrund — but reason includes the Ungrund as its prior unity
Freedom independence of will from desire (honor-principle) capacity for good and evil; intelligible act outside time
Freedom's possibility incognoscible; known only as actuality grounded in severability of principles + eternal self-positing
Reason in spiritual matters inadequate (Jacobi) "fully adequate to expose every error" (Schelling, line 671)
Method leap-of-faith out of system system includes what leap reaches

The 1812 break: Memorial

After 1811's On Divine Things and Their Revelation, in which Jacobi accused Schelling (and German Idealism more broadly) of disguised atheism, Schelling published F. W. J. Schelling's Memorial to Mr. Friedrich Heinrich Jacobi's Writing on the Divine Things etc. and to the Accusation Made against Him Therein Regarding an Intentionally Deceiving and Lying Atheism (1812). This is the only other substantial work Schelling published in his lifetime after the Freedom Essay; the polemical title alone signals the intensity of the break.

The substance of the dispute: Jacobi claimed that Schelling's identity-philosophy and Freedom Essay were covertly atheist (Spinozism dressed in theological clothing). Schelling countered that Jacobi's anti-rationalism was covertly theological dogmatism dressed in philosophical clothing. Both charges were intemperate; the philosophical content was real.

The break is historically the third pantheism debate (after 1785 and the 1799 "atheism controversy" against Fichte). It effectively ended the Schelling-Jacobi institutional relationship at the Bavarian Academy.

The English-Romantic and post-Kantian reception

Jacobi's influence on later philosophy:

  • Kierkegaard: the salto mortale anticipates the "leap of faith" of Fear and Trembling (Jacobi is one of Kierkegaard's named sources).
  • Hegel: criticizes Jacobi extensively in the Encyclopedia and the Wissenschaft der Logik — Jacobi's immediacy is one of the WdL's standing targets.
  • Schopenhauer: dismissive of Jacobi as the "salvation of philosophy through animal faith."
  • Heidegger: takes Jacobi's salto mortale seriously (1957 Identität und Differenz; 1962 Zeit und Sein) as one form of confronting being's priority over thinking.
  • 20th-century pragmatism / Putnam: rediscovery of Jacobi as a serious post-Kantian alternative.

Connections

  • initiates the Pantheismusstreit via the 1785 Spinoza Letters
  • is the primary anti-rationalist opponent in schelling-1809-freedom-essay — the position Schelling must overcome to show that system and freedom are compatible
  • contributes "From On the Doctrine of Spinoza in Letters to Mr. Moses Mendelssohn" as Supplementary Text 4 to schelling-1809-freedom-essay
  • contributes "On Human Freedom" (1789) as Supplementary Text 5 to schelling-1809-freedom-essay
  • stages Lessing as the Spinozist confessor in the Spinoza Letters
  • opposes Baader on the question of reason-and-evil (Jacobi: reason cannot be put to evil use; Baader rebuts in Supplementary Text 2 to the Freedom Essay)
  • opposes Mendelssohn in the Pantheismusstreit — Mendelssohn defends a "purified pantheism"; Jacobi rejects it
  • is criticized by Schelling in the 1812 Memorial — the polemical break
  • anticipates the Kierkegaardian leap of faith; Kierkegaard cites Jacobi as a named source
  • is criticized by Hegel in the WdL — Jacobi's immediacy doctrine is one of the standing targets
  • is taken seriously by martin-heidegger in Identität und Differenz (1957) and Zeit und Sein (1962) as one form of confronting being's priority over thinking
  • bears on existing live claim claims#wegdenken-incorporation-being-precedes-thinking — Jacobi's "substance is the source of thinking" is a proto-formulation of the priority-of-being thesis

Open Questions

  • Whether Jacobi's reporting of Lessing's Spinozist confession is reliable — Mendelssohn denied; the historical record is Jacobi's account alone. The philosophical content of the Pantheismusstreit does not depend on the biographical accuracy.
  • Whether Jacobi's salto mortale is genuinely irrational or only post-rational — Jacobi insists the leap is into positive faith-content, not into incoherence. Whether this distinction can be sustained is contested.
  • Whether Jacobi's position is best read as a precursor to Kierkegaard or as a German-Idealist-internal alternative — Schelling clearly treats Jacobi as the alternative within post-Kantianism; Kierkegaard reads Jacobi as the precursor to existential leap-of-faith.
  • Whether Schelling's Freedom Essay genuinely overcomes Jacobi's challenge — Heidegger and Žižek both diagnose the attempt as an impasse (Scheitern); whether the impasse is productive depends on whether reason can include what Jacobi says only the leap can reach.

Sources

  • schelling-1809-freedom-essay — primary anchor. Two Jacobi texts as Supplementary Texts 4 and 5: Spinoza Letters excerpts (raw lines ~1009–1151) and On Human Freedom (raw lines ~1153–1283). Editors' Introductory Note (raw lines ~1865–1875) frames Jacobi as the primary opponent. Schelling's note 21 (raw line ~1491) on the cooling and break of the Schelling-Jacobi relationship.
  • Implicit anchors: Mendelssohn's Morning Hours (1785, not in raw/); Kant's What is Orientation in Thinking? (1786, not in raw/); Schelling's 1812 Memorial (not in raw/).