Though a survey of the idea itself of the good [agathon] may be of no service to the arts [techne], and for the common purposes of the merely animal life [zoe], yet we may say with Plato in the 7th book of his Republic, that “He who is not able by the exercise of his reasoning power [dianoia] to define the idea of the goody separating it from all other objects, and piercing, as in a battle, through every kind of argument; endeavouring to confute, not according to opinion [doxa], but according to essence [ousia], and proceeding through all the dialectical energies [dialektike] with an unshaken reason, is in the present life sunk in sleep, and conversant with the delusions of dreams [hypnos] ; and that before he is roused to a vigilant state, he will descend to Hades, and be overwhelmed with a sleep perfectly profound.”