It is worth noting that the past experience on which all our judgments about cause and effect depend can operate on our mind so imperceptibly that we don’t notice it, and it may even be that we don’t fully know it. A person who stops short in his journey when he comes to a river in his way foresees the consequences of going forward; and his knowledge of these consequences comes from past experience which informs him of certain linkages of causes and effects. But does he reflect on any past experience, and call to mind instances that he has seen or heard of, in order to discover how water effects animal bodies? Surely not! That isn’t how he proceeds in his reasoning. ·In his mind· the idea of •water is so closely connected with that of •sinking, and the idea of •sinking is so closely linked with that of •drowning, that his mind moves from one idea to the next to the next without help from his memory… . But as this transition comes from experience and not from any primary connection between the ideas, we have to acknowledge that experience can produce a belief—a judgment regarding causes and effects—by a secret operation in which it is not once thought of. This removes any pretext that may remain for asserting that the mind is convinced by reasoning of the principle that instances of which we haven’t had experience must resemble those of which we have. For we here find that the understanding or imagination can draw inferences from past experience without so much as reflecting on it—let alone forming a principle about it and reasoning on the basis of the principle!