Categorical logic is a branch of logic that deals with the relationships between different categories or classes of objects. It uses statements that assert whether certain categories are included in others, often expressed in the form of syllogisms. For example, a common syllogism might state that "All humans are mortal" and "Socrates is a human," leading to the conclusion that "Socrates is mortal." This type of logic is foundational in philosophy and mathematics, helping to clarify reasoning and argumentation. It is often associated with the work of philosophers like Aristotle, who developed the initial principles of categorical reasoning. Categorical logic is useful in various fields, including computer science and linguistics, for structuring information and understanding relationships.