Blog entry from a friend

A Philosophical Drive-by: “Posted: No Trespassing” by Daniel Hieber

It may not seem so at first, but there is a philosophical lesson about truth embedded in this sign. If you are at least mildly intelligent, you are probably somewhat amused by the wording of that sign. (If you are not at least mildly intelligent, then you are probably amused by Adam Sandler movies.) The source of the amusement in the sign, of course, is that a simple “NO TRESPASSING” would have sufficed to convey the intended message; for once you post the sign, it is obvious that it has been posted. One need not make the pronouncement that one has posted a sign that one has posted. That is to say, one adds nothing to a posted “NO TRESPASSING” sign by adding the word “POSTED” to it. To say that a posted sign has been posted is utterly redundant.

We are now in position to discuss the redundancy theory of truth. According to this theory—generally attributed to mathematician and philosopher Frank Ramsey—it is redundant to assert the truth of something that is being asserted. For example, if one says, “It is true that Caesar was murdered,” that means nothing more than “Caesar was murdered.” In that example, the predicate “is true” doesn’t carry any additional weight, and it doesn’t add anything to what was being said. Put in its most simple terms, when I say, “It is true that Caesar was murdered,” I am using pleonastic and circumlocutory verbiage; for I could just as well—and more concisely—have said, “Caesar was murdered.” Thus, just as we saw in the case of the “POSTED NO TRESPASSING” sign, redundancy raises its ugly head . . . again.