Socrates finally manages to get Meno to react despite not selecting one of the choices Meno gave him regarding the sort of thing arete (virtue) is. Meno reacts to the suggestion that someone not knowing Meno at all would not know what sort of person Meno is, but immediately turns to the scoop that Socrates doesn't know at all what arete (virtue) is ( for which reason Socrates claims not to know what sort of thing arete is).
