Why is x F?
εἶναί τι ἕκαστον τῶν εἰδῶν καὶ τούτων τἆλλα μεταλαμβάνοντα αὐτῶν τούτων τὴν ἐπωνυμίαν ἴσχειν (Phaedo, 102a10-b2)
Each of the Forms exists and other things acquired their name by having a share in them.
The 1st part of this statement (claiming the safe but uninformative αἰτία):
∀F∀x∃ϕ (Fx ↔ x participates ϕ)
ϕ: Form, x: individual, F: immanent character designated by adjective or abstract noun.
The 2nd part of this statement (claiming the clever αἰτία):
Instead of mentioning just one Form, ϕ, Socrates now refers us also to another, Γ, so related to ϕ, that whatever is “named after” Γ, will also be name after ϕ (103e-104b). X is F because it participates in Γ and Γ entails ϕ.
Two Mistaken Interpretations of the Safe but Ignorant αἰτία
a. Teleological αἰτία: “Socrates makes it abundantly clear that he is still, at the time of speaking, deprived of the teleological aitia he had been looking for” (87-88).
b. Efficient αἰτία: if Plato’s Forms were efficient causes as Aristotle expounded, how could a certain Form ϕ have the specific causal effect on a certain individual a, which would account for its being F rather than not-F, without having the same effect on all other objects, including those which are not-F?
Logical αἰτία
To avoid the above absurd consequence, we should “credit the Forms with the power to act selectively on different objects in the universe, directing their casual influence to some of them, withholding it from others” (90).
ϕ is that because of which [δι’ ὅτι; 100d1] x is F; it is that which makes [ποιεῖ; 100d5] x to be F; it is the αἰτία of x’s being F.
Vlastos claims that ϕ makes x to be F only in a logical sense of “make”.
Why is this figure a square?
Forms explains why a figure, for example, happens to have—not, how or why it happens to get—the shape that meets the logical conditions for being square. “It is the logical function of Squareness that does the explanatory work of the safe αἰτία” (92).
The logical αἰτία is simultaneously a metaphysical one for Plato, since the definition of a concept is the “account of the essence” of its Form.
Why Logical Interpretation of the Safe αἰτία Makes Good Sense?
Though uninformative, the safe is not useless, for it saves us from misdirecting our search for αἰτία to irrelevant physical factors. The reason why six puzzles arise is due to the fact that “Socrates was confusing physical αἰτία with logical ones” (99). E.g., the reason why one is taller another by a head is not because of the head, but because of her tallness.
The Clever αἰτία
Instead of mentioning just one Form, ϕ, Socrates now refers us also to another, Γ, so related to ϕ, that whatever is “named after” Γ, will also be name after ϕ (103e-104b).
x is F because it participates in Γ and Γ entails ϕ. E.g., a is hot because it participates in the Form Fire and the Form Fire entails the Form Hotness.
Γ (Fire) entails ϕ (Hotness)
This entailment cannot be credited with causal agency.
But this entailment has causal implication, namely, Γ (the Form Fire) implies ϕ (the Form Hotness).
According to Vlastos, Plato reduces physical necessity to logical necessity. E.g., if we raise the temperature beyond a certain point, snow “must” change to water.
However, a theory such as this is not likely to get a sympathetic hearing from philosophers nowadays.
Vlastos’ Conclusion
Why is the distinction between the safe αἰτία and the clever αἰτία important? Plato “uses the ‘safe’ αἰτία to explode pseudo-problems which arise when the categorical difference between logical and physical αἰτία is ignored” (110).
Seems like Plato confuses physical necessity with logical necessity? “There is no confusion here, but the expression of his firm conviction that all intelligible necessity, physical no less than mathematical, must be grounded on logical necessity” (110).
Now, under Vlastos’ distinction between the ignorant αἰτία and the clever αἰτία, how would the Final Argument be reconstructed?
Method of Hypothesis
According to Vlastos, instead of directly investigating the truth of proposition p, “you hit upon another proposition h (the hypothesis), such that p is true iff h is true, and then investigate the truth of h, undertaking to determine what would follow if h were true and, alternatively, if it were false.”
The final argument consists in an application of the method of hypothesis. The hypothesis chosen is the theory of Forms, or more precisely the idea that Forms function as explanations or causes of phenomena: beautiful things are beautiful by virtue of the Beautiful.
Reconstruction of the Final Argument
1. Hypothesis of the safe but ignorant αἰτία: Instead of investing the truth of proposition p “the soul is the explanation of a thing that is alive”, we hit upon another hypothesis proposition h “the Hot is the explanation of a thing that is hot” such that p is true iff h is true. So now we turn to investigate the truth of h.
2. Hot things are hot by virtue of the Hot.
3. Hence the Form Hot is the explanation of hot things
Reconstruction of the Final Argument
4. The safe but ignorant αἰτία can be used to generate a more specific model of causation, which Vlastos called the clever αἰτία: “hot things are hot by virtue of fire, provided that wherever the fire exists, it always heats things in its vicinity, being itself hot and never cold”.
5. Hence the fire is the explanation of hot things.
6. Hence the soul is the explanation of living things.
7. If the soul is the explanation of a living thing, then it is always alive and can never be dead.
8. Hence the soul must be immortal and imperishable.
My Comments
a. Is the clever αἰτία more clever than the ignorant αἰτία at all? According to Vlastos’ construal of the safe but ignorant αἰτία, only the Form Hotness and nothing else can make things hot. The Form Fire hence is at best a pseudo-αἰτία, because it by itself can never make things hot. It is actually the Form Hotness dwelling in the Fire that makes things hot.
b. Vlastos has been operating two different senses of “logical necessity”. For, on the one hand, Vlastos claims that the Form Hotness has the force of logical necessity to make things hot, which is based on the principle of synonym. On the other hand, the logical necessity by which the Form Fire entails the Form Hotness is based on physical necessity rather than the principle of synonym.
c. If the final argument aims to show that the soul is the explanation of the living things and hence can never be dead, and if Vlastos’ two models of αἰτία are meant to be an account for the soul’s causal role, then the crucial step of this argument would be to establish the connection between the Form Soul and the Form Alive. But, can logical necessity satisfy us in explaining this connection? We are asking why the soul is always alive and never dead. Does the claim that the Form Soul logically entails the Form Alive answer our question?
Reference
Vlastos, “Reasons and Causes in the Phaedo,” Philosophical Review, 1969, 78 (3): 291-325.
