[126] Now, irrigation may be looked upon in a two-fold light: with regard to that which irrigates, and with regard to that which is irrigated. And might one not say that each of the outward senses is irrigated by the mind as by a fountain, which widens and extends all their faculties, as if they were so many channels for water? No one, therefore, in his senses would say, that the eyes see, but that the mind sees by means of the eyes; or that the ears hear, but that the mind hears by the instrumentality of the ears; or that the nostrils smell, but that the predominant part of man smells through the medium of the nostrils.