 Of the three associative principles, causation is the strongest, and the only one that takes us “beyond our senses” (T 1.3.2.3/74). It establishes links between our present and past experiences and our expectations about the future, so that “all reasonings concerning matters of fact seem to be founded on the relation of Cause and Effect” (EHU 4.1.4/26). Taking aspirin in the past has relieved my headaches, so I expect that the aspirin I just took will soon relieve my present headache. Hume also makes clear that causation is the least understood of the associative principles, but he tells us, “we shall have occasion afterwards to examine it to the bottom” (T 1.1.4.2/11).