He promoted the idea that it is the necessary result of Enlightenment thought and the philosophical systems of Baruch Spinoza, Immanuel Kant, Johann Gottlieb Fichte and Friedrich Wilhelm Joseph Schelling.

In this sense, Jacobi can be seen to have anticipated present-day writers who criticize secular philosophy as relativistic and dangerous for religious faith.

Jacobi, of a retiring, meditative disposition, associated himself at Geneva mainly with the literary and scientific circle (of which the most prominent member was Georges-Louis Le Sage).

The experience as well as its aftermath led to the publication of two essays in which Jacobi defended Adam Smith's theories of political economy.

His next important work, David Hume über den Glauben, oder Idealismus und Realismus (1787), was an attempt to show not only that the term Glaube had been used by the most eminent writers to denote what he had employed it for in the Letters on Spinoza, but that the nature of the cognition of facts as opposed to the construction of inferences could not be otherwise expressed.

In this writing, and especially in the Appendix, Jacobi came into contact with the critical philosophy, and subjected the Kantian view of knowledge to searching examination.

[2] In 1787, Friedrich Heinrich Jacobi addressed, in his book On Faith, or Idealism and Realism, Kant's concept of "thing-in-itself."

Jacobi and the Pantheism Controversy he ignited remain important in European intellectual history, because he formulated (albeit critically) one of the first systematic statements of nihilism and represents an early example of the death of God discourse.

[2] In 1811 appeared his last philosophic work, directed against Friedrich Schelling specially (Von den göttlichen Dingen und ihrer Offenbarung), the first part of which, a review of the Wandsbecker Bote, had been written in 1798.

A bitter reply from Schelling was left without answer by Jacobi, but gave rise to an animated controversy in which Fries and Baader took prominent part.

A fundamental view which underlies all his thinking is brought to bear in succession upon those systematic doctrines which appear to stand most sharply in contradiction to it, and any positive philosophic results are given only occasionally.

From the basis of immediate experience or perception thought proceeds by comparison and abstraction, establishing connections among facts, but remaining in its nature mediate and finite.

[2] The principle of reason and consequent, the necessity of thinking each given fact of perception as conditioned, impels understanding towards an endless series of identical propositions, the records of successive comparisons and abstractions.

It is impossible that there should be liberty, for if so the mechanical order of phenomena, by means of which they are comprehensible, would be disturbed, and we should have an unintelligible world, coupled with the requirement that it shall be understood.

It was not until 1990s and 2000s, that the work of scholars such as Dieter Henrich, and specially Birgit Sandkaulen in her book Grund und Ursache (2000) revitalized the systematic reading of Jacobi for the first time.