judgment about empirical possibility is based on experience and will often be rather uncertain; there will be no sharp boundary between possibility and impossibility.
Is the possibility of verification which we insist upon of this empirical sort? In that case there would be different degrees of verifiability, the question of meaning would be a matter of more or less, not a matter of yes or no. In many disputes concerning our issue it is the empirical possibility of verification which is discussed; the various examples of verifiability given by Professor Lewis, e.g., are instances of different empirical circumstances in which the verification is carried out or prevented from being carried out.
Many of those who refuse to accept our criterion of meaning seem to imagine that the procedure of its application in a special case is somewhat like this: A proposition is presented to us ready made, and in order to discover its meaning we have to try various methods of verifying or falsifying it, and if one of these methods works we have found the meaning of the proposition; but if not, we say it has no meaning. If we really had to proceed in this way, it is clear that the determination of meaning would be entirely a matter of experience, and that in many cases no sharp and ultimate decision could be obtained. How could we ever know that we had tried long enough, if none of our methods were successful? Might not future efforts disclose a meaning which we were unable to find before?
This whole conception is, of course, entirely erroneous. It speaks of meaning as if it were a kind of entity inherent in a sentence and hidden in it like a nut in its shell, so that the philosopher would have to crack the shell or sentence in order to reveal the nut or meaning. We know from our considerations in section I that a proposition cannot be given ‘ready made’; that meaning does not inhere in a sentence where it might be discovered, but that it must be bestowed upon it. And this is done by applying to the sentence the rules of the logical grammar of our language, as explained in section I. These rules are not facts of nature which could be ‘discovered’, but they are prescriptions stipulated by acts of definition. And these definitions have to be known to those who pronounce the sentence in question and to those who hear or read it. Otherwise they are not confronted with any proposition at all, and there is nothing they could try to verify, because you can’t verify of falsify a mere row of words. You cannot even start
