Plato's Argument from Recollection from the Phaedo

The Argument from Recollection: Phaedo 72e-77a


1. If a person is reminded of anything, he must first know that thing at one time or another. (73c 1-3)

2. Definition: Recollection is knowledge that comes about in this way: when a person upon seeing one thing not only becomes conscious of it, but also of something else which is a different object of knowledge. (73c 5-10)

3. We know that there are such things as absolute equality (the forms). (74a 8-11)

4. We get this knowledge of these forms from seeing particular things which are quite different from forms and absolute qualities. (74b 5-7 and ff. up to 74d)

5. By (2): This knowledge is knowledge by recollection. (74d 1-2)

6. By (1): We must have had previous knowledge of the forms and absolute qualities. (74e 1-3 and ff.)

7. From (1) through (6): We must have had knowledge of absolute qualities (forms) before the fist time we were reminded of them by perception. (75a 1-2)

8. It is impossible for us to have gained this original knowledge of absolute qualities in any other way than through recollection prompted by the senses. (75a 4-7)

9. Before we begin to see or hear we must have somewhere aquired this knowledge of absolute qualities. (75b 3-7)

10. We begin to see and hear at birth. (75b 9-10)

11. By (9) and (10): We aquired our knowledge of forms before birth. (75c4)

Therefore, 

12. Our souls had existence before birth.