Philosophers for several millennia have tried to pinpoint the nature of truth. Aristotelian-Thomistic philosophers have emphasized that truth involves a correspondence of the mind to reality. This theory, dubbed “realism,” focuses on the human power of abstraction of generalities from particulars – e.g., developing the concept, “flower” from experience of geraniums and roses, and the concept of “living things” from experience of flora and fauna, and then making proper judgments.
But in the 18th century, Immanuel Kant brought to a head the Cartesian emphasis on subjectivity by theorizing that the things we know have to correspond to mental categories that result from the laws of logic. For example, our logic distinguishes particular propositions from universal propositions, so we have to think in terms of “some,” “all,” “totalities,” etc.