Ia:
On true self-love (II-II.25.7)
Ib:
On human happiness (I-II.2.1-8; 3.8; 5.8; 4.5&7,8; 5.2&3&5&1)
II: On the free will (I.83.1; D.V. 24.1&2)
III: On the soul's immateriality and existence (I.75.1-7)
IV: On the soul as form and intellect (I.76.1; 76.2,3,5,8)
V: On the soul's knowledge (I.84.1-4&6-8;85.1-2&5-6)