It is also the case that an increasingly broad range of ways of acting and being acted on is attributed to the soul.
The argument at the end of Book 1 proceeds by attempting to prove an interim conclusion that is unnecessarily strong, namely that the just person is happy, whereas the unjust person is wretched.
The argument begins with the premise that things perform their function well if they have the virtue appropriate to them, and badly if they have the relevant vice 353c.