 As the being of real universals coincides with the being of their corresponding individuals, real universals can be said to be everlasting because of the continuous succession of their individuals, and also really identical with them. But universals and individuals are also formally different from each other, as they have distinct constitutive formal principles, and therefore different properties (ibid., pp. 91–92). The most important among universal signs are mental universals, which are both the acts of intellection through which our mind grasps the nature of universal forms and the concepts through which it connects general names with the things to which they refer (ibid., pp. 68–69).