All of your learning is useless to you until you have made it a habit of mind. Mental habits are like a team of stonemasons working on a medieval cathedral. Not much can be accomplished without their skilled hands. Habits of mind transform reflective thought into concrete action. Where do our mental habits come from? The various academic disciplines-history, language studies, science, and mathematics-furnish us with many of our most cherished habits. History teaches us how to place events in a larger social context of understanding. Language studies guide us in expressing ourselves by using clear and concise speech and written skills. Science cultivates the mental habits of curiosity and careful observation of nature. Mathematics alerts us to the patterns formed by numbers in the fabric of the cosmos. These four disciplines provide the core habits underlying the expansion of human knowledge and the promotion of cultural well being.