In 1733, the German writer Friedrich Lebrecht Goetz used the word "nihilism" as a literary term. Swiss esotericist Jacob Hermann Obereit also used the word in 1787, German thinker Friedrich Heinrich Jacobi did in 1799. This is where it first became part of philosophy. The belief that no one can know true reality is what Obereit called "nihilism". He used this definition to call the German thinker Immanuel Kant a nihilist. This was because Kant said people cannot be certain of real things, but can only be certain about their experience of real things. Jacobi also used this definition to say Kant and his followers were nihilists. For example, he famously called the German thinker Johann Gottlieb Fichte a nihilist. Jacobi thought both the humanism and German idealism that had come out of the Age of Enlightenment were kinds of nihilism. According to him, these so-called rational philosophies were the complete opposite of rational.