Immanuel Kant
Kant published other important works on ethics, religion, law, aesthetics, astronomy, and history. These include the "Universal Natural History" (1755), the "Critique of Practical Reason" (1788), the "Metaphysics of Morals" (1797), and the "Critique of Judgment" (1790), which looks at aesthetics and teleology.
Immanuel Kant
One may now ask: How many possible judgments are there? Kant believed that all the possible propositions within Aristotle's syllogistic logic are equivalent to all possible judgments, and that all the logical operators within the propositions are equivalent to the moments of the understanding within judgments. Thus he listed Aristotle's system in four groups of three: quantity (universal, particular, singular), quality (affirmative, negative, infinite), relation (categorical, hypothetical, disjunctive) and modality (problematic, assertoric, apodeictic). The parallelism with Kant's categories is obvious: quantity (unity, plurality, totality), quality (reality, negation, limitation), relation (substance, cause, community) and modality (possibility, existence, necessity).