The following work attempts to review the issue of the universals such as Thomas Aquinas did in his work De ente et essentia. It pretends to elucidate the specific way of being of the universals as an accident of the absolute essence present in the mind. This does not lead to nominalism because the understood essence is identical to the nature existing in the particular. This way of being of the essence is what precisely allows knowledge as an intentional possession of reality.