Immanuel Kant refers to Spinoza repeatedly, and almost always quite critically, in his published and unpublished writings. (Kant does praise Spinoza for his allegedly upstanding moral character. See below.) Kant’s comments on Spinoza are usually quite brief and display only superficial knowledge of his philosophy. He does not refer to specific parts of Spinoza’s works, strengthening the impression that he knew Spinoza only secondhand through the accounts of others. (This is the conclusion of Marshall 2021; Boehm 2014 argues for a more extensive engagement with Spinoza on Kant’s behalf.) For instance, Kant displays no awareness of the complexity of Spinoza’s doctrine of attributes, attributing to him merely the view that Thought and Extension are “properties [Eigenschaften]” or “predicates Prädicate]” of God (AA28:60, 1052).