March 1987
One. Suppose that someone says, “I have and use successfully a private language.” We ask: “Is this language made up of rules? (Standard patterns of symbol usage).” He will probably reply, “Indeed it is.” And we say: “How are you sure that your language does not drift, that you use it consistently through time?” He might say, “It is a genuine language. It has regularity. It is not just my whim as to how I use it.” Then we come to the point: “What is the evidence that you use this private language you have consistently, other than your own testimony?” If intelligent, he will likely say, “My private language is a technical language. Every term is carefully defined according to the essence involved. When I use a term, I can check all the essential items to be sure that I am using the term consistently and correctly.” We counter: “Are there any undefined, primitive terms in your language?” Being an honest person he admits, “Yes there are, since every language must have undefined primitives.” We add: “So you cannot then be sure that the meaning of these primitives does not drift?” He retorts, carefully, “While it is true that I cannot be sure that the definitions of my primitive terms do not drift, I am sure that my private language system is sound and does not drift because I am able to do things with it in the real world. Nature responds to my formulae. I am justified in saying that I have a genuine private language because it works.” Then we reach for the clincher: “And how are you assured that it works?” He proudly responds, thinking he has won the argument, “Because nature produces for me exactly what I want when I use my fomulae on it. Thus my private language constitutes a genuine private language, because no other human being knows it and I can use it to accomplish just what I desire to accomplish.”
For all of his intelligence and good will, our friend does not see two things. First, he does not see that his desires may be shifting, and that nature gives him what he desires because he has come to desire what nature gives him. He cannot produce any evidence except his own word that his desires have not changed. Second, if nature does respond to his formulae and give him desired results, that means that he and nature have a successful communication going. He communicates to nature what he desires, and nature communicates back, filling those desires. That is not a private language; it is only private relative to other human beings, but public in relation to himself and nature, the two together seen as a community. So there is no private language as yet.
Suppose our friend pulls out his last resort and says, “But I do have a private language with God. I have made up my own terminology and syntax, and I write and speak to God in that language which is completely unknown to any other human being.” We need only inquire: “And does God then speak back to you in that language, and using that language does he enable you to foreknow the future and to accomplish that which you could not do by your own power?”
If he says, “No. God never speaks to me.” He has a problem. He then thinks he has “a language,” but cannot assure himself or anyone else that he is using it consistently. Thus no private language, only private mumblings. If he says, “Yes. All of those things happen and more,” then he has given his case away again. For if he speaks to God and God speaks back to him through that process, he learns things he did not before, knows and does things he could not before do, then his language is not private but public, defining the community to which this language is not private but public, defining the community to which this language is public to be himself and God. Only where there is a community that serves as a check and balance on our language can we know that what we are doing is using a language. Otherwise what we say or do is meaningless babble. Thus, there is no private language.