§ 20. A judgment of perception is a connection of perceptions in a subject's mind. For example, "When the sun shines on a stone, the stone becomes warm." A judgment of perception has no necessary universality and therefore no objective validity. A judgment of perception can become a judgment of experience, as in "The sun warms the stone." This occurs when the subject's perceptions are connected according to the form of a pure concept of the understanding. These pure concepts of the understanding are the general forms that any object must assume in order to be experienced.