A Puzzle about Definitions
Socrates has told us he knows how to reject faulty definitions. But
how does he know when he has succeeded in finding the right definition?
Meno raises an objection to the entire definitional search in the form
of (what has been called) "Meno's Paradox," or "The Paradox of Inquiry"
An Objection to Inquiry
The argument reformulated:
If you know what you're looking for, inquiry is unnecessary.
If you don't know what you're looking for, inquiry is impossible.
Therefore, inquiry is either unnecessary or impossible.
An implicit premise:
Either you know what you're looking for or you don't
know what you're looking for.
And this is a logical truth. Or is it? Only if "you know what you're looking
for" is used unambiguously in both disjuncts.
Evaluating the Argument
There seems to be an equivocation in "you know what you're looking for":
You know the question you wish to answer.
You know the answer to that question.
Using sense (A), (2) is true, but (1) is false; using sense (B), (1) is true,
but (2) is false. But there is no one sense in which both
premises are true. And from the pair of true premises, (1B) and
(2A), nothing follows, because of the equivocation.
To see the ambiguity, consider the question: "Is it possible for you to know
what you don't know?"
In one sense, the answer is "no." You can't both know and not know the same
thing. (Pace Heraclitus.) In another sense, the answer is "yes." You
can know the questions you don't have the answers to.
How Inquiry is Possible
So this is how inquiry is possible. You know what question you want to answer
(and to which you don't yet know the answer); you follow some appropriate
procedure for answering questions of that type; and finally you come to know
what you did not previously know, viz., the answer to that question.
The argument for Meno's Paradox is therefore flawed: it commits the
fallacy of equivocation. But beyond it
lies a deeper problem. And that is why Plato does not dismiss it out of hand.
That is why in response to it he proposes his famous "Theory of Recollection."
The Theory of Recollection
Concedes that, in some sense, inquiry is impossible. What appears to be
learning something new is really recollecting something already
This is implausible for many kinds of inquiry. E.g., empirical inquiry:
Who is at the door?
How many leaves are on that tree?
Is the liquid in this beaker an acid?
In these cases, there is a recognized method, a standard procedure, for arriving
at the correct answer. So one can, indeed, come to know something one did
not previously know.
But what about answers to non-empirical questions? Here, there may
not be a recognized method or a standard procedure for getting answers. And
Socrates' questions ("What is justice," etc,) are questions of this type.
Plato's theory is that we already have within our souls the answers to such
questions. Thus, arriving at the answers is a matter of retrieving
them from within. We recognize them as correct when we confront them.
(The "Aha!" erlebnis.)
Plato's demonstration of the theory
Plato attempts to prove the doctrine of Recollection by means of his interview
with the slave-boy.
Note that it is non-empirical knowledge that is at issue: knowledge of a
geometrical theorem. (A square whose area is twice that of a given square
is the square on the diagonal of the given square.)
How successful is Plato's proof of the doctrine of recollection?
The "Proof" of Recollection
Call the geometrical theorem in question P. Plato assumes:
At t1 it appears that the boy does not know that P.
At t2 the boy knows that P.
The boy does not acquire the knowledge that P during the interval
between t1 and t2.
Plato thinks that (2) is obviously correct, since at t2 the boy can give
a proof that P. And he thinks that (3) is correct since Socrates doesn't
do any "teaching" -- he only asks questions.
But (2) and (3) entail that the appearance in (1) is mistaken -- at
t1 the boy did know that P, since he knows at
t2 and didn't acquire the knowledge in the interval between
t1 and t2.
Crucial assumptions by Plato:
Socrates didn't do any teaching.
The only way to acquire new knowledge is to be taught it.
Both assumptions are dubious:
Socrates asks leading questions. He gets the boy to notice the diagonal
by explicitly bringing it up himself.
The disjunction -- either the boy was taught that P or he already
knew that P -- may not be exhaustive. There may be a third alternative:
reasoning. That is, deducing the (not previously noticed)
consequences of what you previously knew.
Interpretations of "Recollection"
Plato certainly thinks he has proved that something is innate, that
something can be known a priori. But what? There seem to be three
possibilities, in order of decreasing strength:
Propositions: such as the geometrical theorem P. They are literally
in the soul, unnoticed, and waiting to be retrieved. According to this reading
of "recollection", propositions that can be known a priori are literally
Concepts: such as equality, difference, odd,
even, etc. We are born with these - we do not acquire them
from experience. We make use of these when we confront and organize our raw
experiences. According to this reading of "recollection", there are a
priori concepts that we have prior to experience.
Abilities: such as that of reasoning. We are born with the innate
ability to derive the logical consequences of our beliefs. We may form our
beliefs empirically, but we do not gain our ability to reason empirically.
According to this reading of "recollection", there is no innate knowledge
and there are no a priori concepts. All but the most hard-boiled
empiricist can accept (c).
Plato talks as if he has established (a), but the most he establishes in
the Meno is (c). But perhaps that is all he is intending to establish
(cf. Vlastos article, "Anamnêsis (Recollection) in the
Meno," on reserve).
In the Phaedo, Plato offers a different argument that appears to be
aiming at (b). This is the argument from imperfection, which purports
to show that the imperfection of the physical world proves that we must have
a priori concepts that cannot be derived from experience. Rather,
the very possibility of our having experience at all requires that we already
have these concepts.
So even if "recollection" is only inference misdescribed, there is still
room for Plato to argue that inference requires the use of concepts that
cannot themselves be acquired empirically.