Even though throughout his works Aquinas uses at least ten different words to talk
about the nature of truth, his preferred way of defining truth is adaequatio, as in
his classic definition adaequatio rei et intellectus. Why does he prefer this one?
This paper gives two possible reasons: 1) the connection between adaequatio and
equality, understood as a mean or middle between more and less, and 2) the
connection between adaequatio and the second act of the intellect. The paper will
thus be divided into two parts.
