  One effect can be found by interpreting the form of the good that the philosopher comes to grasp, since this should shape the philosopher’s rational conception of what is good for her. The form of the good is  a shadowy presence in the Republic, lurking behind the images of the Sun, Line, and Cave. But it is clear enough that Socrates  takes goodness to be unity (Hitchcock 1985). He explicitly emphasizes that a virtuous  person makes himself a unity (443c–e) and insists that a city is made good by being made a unity (462a–b). The assumption that goodness is  unity also explains why mathematics is so important to the ascent to  the good (through mathematics an account of the one over the many is  learned) (cf. Burnyeat 2000), why the good is superior to other forms (the good is the  unity or coherence of them, and not another alongside them), why the  other forms are good (by being part of the unified or coherent  order), and why goodness secures the intelligibility of the other  forms (they are fully known teleologically). (It also comports with  the evidence concerning Plato’s lecture on the good (e.g.,  Aristoxenus, Elementa Harmonica II 1; cf. Aristotle  Eudemian Ethics 1218a20 and Metaphysics 988a8–16  and b10–15.) So the philosophers, by grasping the form of the good,  will recognize goodness in themselves as the unity in their souls.  They will see that the harmony or coherence of their psychological  attitudes makes them good, that each of their attitudes is good  insofar as it is part of a coherent set, and that their actions are  good insofar as they sustain the unity in their souls (cf. 443e).