The German philosopher Immanuel Kant (1724–1804) distinguishes between judgments of perception and judgments of experience. Judgments of perception are judgments that lack objective validity, i.e. they are only valid as subjective pronouncements, while judgments of experience refer to judgments that possess objective validity. Initially all of our judgments are judgments of perception. If a particular judgment conforms to a certain thing, every judgment about this thing has to be in keeping between themselves. If this de facto is the case, our judgment of perception becomes a judgment of experience.
If I put my hand on a stone on a sunny day and exclaim: “This stone is so warm”, my judgment counts as a judgment of perception. One might thence ask oneself why the stone is warm. By adding a concept of understanding to this sentence it may look like this: “The sun warms the stone.” The verb “warms” is with necessity associated with the noun “sun” or “sunshine”. While applying a concept of understanding, a kind of causal attribute, things are added to one another, and the entire judgment becomes synthetic. The judgment “The sun warms the stone” thus becomes, with necessity, universally applicable, i.e. objectively valid, and it turns from a judgment of perception into a judgment of experience.