From the Beginning to Plato

FROM THE BEGINNING TO PLATO 121
The Choice of Ways
The narrator’s ‘finding out’ of reality is represented as a matter of simply
listening to the goddess. Yet there are hints that his was an active pursuit of the
truth; it was his own desire that started him off. The metaphor of travel, and the
implication of active pursuit in ‘finding out’, are now carried further. There is
talk of ‘ways of enquiry’; the listener is warned off from two of these ‘ways’,
and told of ‘signs’ that appear in the course of the third. The exposition
envisages an active rethinking, by the listener, of the course of Parmenides’
thinking.
Why the active participation of the listener is needed becomes clear from what
follows. The exposition concerning reality is in the form of a deductive
argument, which one cannot properly follow and grasp, without recreating it in
the movement of one’s own mind. The ‘ways of enquiry’ are ‘lines’ (as we say)
of argument, each following deductively from its own initial premiss, by the
mention of which it is, naturally enough, identified in the exposition. Rigorous
deductive arguments were possibly already in use in mathematics; but they must
have been novel to most of Parmenides’ contemporaries. Hence the efforts
Parmenides makes, using the metaphor of the ‘ways’, to keep the course of the
arguments, their interrelation and their overall effect, absolutely clear.
Come then, I will tell you (and you, listen and take in the story!), which
ways of enquiry alone are to be thought: the one, that it is and cannot not
be, is the path of conviction, for it follows along after reality; the other,
that it is not and that it is necessary that it is not—this track, I tell you, is
utterly unconvincing…
(DK 28 B 2.1–6)
This presents, as a starting-point, a choice between two such ways, which are
mutually exclusive. Clearly, though, they are not jointly exhaustive, since there
might also be ways involving unrealized possibilities (‘it is, but might possibly
not be’, ‘it is not, but might possibly be’). In fact, in the sequel, Parmenides will
present only one more way, the ‘way of mortals’, which, as stated, is evidently
self-contradictory. The two named here are apparently the only ones that ‘are to
be thought’; and, of these, one is to be rejected as false.
What is going on here seems to be as follows. Parmenides holds (on what
grounds, remains to be examined) that to speak of unrealized possibilities
involves a contradiction. Hence, taking ‘is it?’ as the basic question at issue,
there can be only two premisses to be considered: ‘necessarily, it is’, and
‘necessarily, it is not’. The ‘way of mortals’, which says that ‘it is and it is not’,
is self-evidently contradictory; it is therefore not ‘to be considered’. None the
less, it is mentioned later, and the reader is expressly cautioned against it,
because it is a popular and appealing way. Of the two ways worth consideration,
the second, which says ‘necessarily, it is not’, also turns out to involve a