From nobody@digitalkingdom.org Sat Dec 05 01:07:39 2009 Received: with ECARTIS (v1.0.0; list lojban-list); Sat, 05 Dec 2009 01:07:40 -0800 (PST) Received: from nobody by chain.digitalkingdom.org with local (Exim 4.69) (envelope-from ) id 1NGqc4-0006AS-7G for lojban-list-real@lojban.org; Sat, 05 Dec 2009 01:07:37 -0800 Received: from mail-yx0-f202.google.com ([209.85.210.202]) by chain.digitalkingdom.org with esmtp (Exim 4.69) (envelope-from ) id 1NGqbC-0005gL-Gg for lojban-list@lojban.org; Sat, 05 Dec 2009 01:06:45 -0800 Received: by yxe40 with SMTP id 40so2930681yxe.28 for ; Sat, 05 Dec 2009 01:06:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:message-id:subject:from:to:content-type :content-transfer-encoding; bh=9KoC3w0U+J0GpqjG7+piUpxZ1tSrCLGOLyqcY46tMAo=; b=YQeDpIVFqkCoREmcegfEQmZ/E8KKVzbb1yD7DdiAchZwqzo75mq1xWrFlxiuQBpCmN KU5/G1+HFI7VJs5j5TVjH5rPxx+CTxmeGy4Rn1UY/WRbpODwLCMnWqPriReX6QQpxCdG CBZyQ0aMB2E/HZgHUu5HQZnYaSv7jX1elWXPo= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type:content-transfer-encoding; b=V11NjXntAHZxWziKIcBo0DQXnavJbh1jjE8U0SWFXGpAZtN0tQZqigoQWYO5mj1Vqc dFSQqUn80BkCkaoPt7r2PChMR/KQMmumqwXAhzEf1EsP5aORgd5W3RSLV5mw+Akuijex fMpKb2E8Ml/8zOgHRXZk44QKbODLPhHcOyQiQ= MIME-Version: 1.0 Received: by 10.90.166.12 with SMTP id o12mr4172786age.110.1260003995596; Sat, 05 Dec 2009 01:06:35 -0800 (PST) In-Reply-To: <925d17560912041829j368963b5y431b13ea2c29aff7@mail.gmail.com> References: <925d17560912030728s34f5a4f7he1ecb295fb7bfacf@mail.gmail.com> <925d17560912041829j368963b5y431b13ea2c29aff7@mail.gmail.com> Date: Sat, 5 Dec 2009 03:06:35 -0600 Message-ID: Subject: [lojban] Re: what's a du'u? From: Thomas Jack To: lojban-list@lojban.org Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from quoted-printable to 8bit by Ecartis X-archive-position: 16629 X-ecartis-version: Ecartis v1.0.0 Sender: lojban-list-bounce@lojban.org Errors-to: lojban-list-bounce@lojban.org X-original-sender: thomasjack@gmail.com Precedence: bulk Reply-to: lojban-list@lojban.org X-list: lojban-list 2009/12/4 Jorge Llambías : > On Fri, Dec 4, 2009 at 10:07 PM, Thomas Jack wrote: >> My real concern is about {du'u}, though. As I understand it, it's a >> predication (where the arguments are things referred to), so that {lo >> du'u la .tom. du la .tom. cu du lo du'u la .tom. du la .tomas.} is >> true given that all the names refer to the same person. > > I don't think it's true in general. It's true only if the sumti "la > tom" and "la tomas" have been assigned the same value outside of the > du'u context. Yes, does my "given that all the names refer to the same person" not take care of this? The problem is that, even if all the names refer to the same person, common English usage (and perhaps common Lojban usage?) suggests that {lo du'u la tom du la tom} and {lo du'u la tom du la tomas} are different (compare to "that tom is tom" and "that tom is thomas" in English). >> I also wonder whether there is evidence to be found in the logs about >> whether people typically would assent to {lo du'u la .tom. du la .tom. >> cu du lo du'u la .tom. du la .tomas.} > > Someone might be willing to assent to that, but if you ask them > whether they really think knowing one amounts to the same thing as > knowing the other they would hopefully soon realize that that can't be > the case, so there has to be some problem with a theory that prredicts > that. My problem is that I don't think there is a problem with such a theory—one such theory is my current favorite. Someone who knows that Tom is Tom, but says they don't believe the proposition that Tom is Thomas, is simply mistaken. I started this thread because one theorist arguing for such a theory suggested that maybe we should speak a language which respects this theory, and I immediately wondered whether Lojban does. Investigating the meanings of {du'u} and {bridi} suggested that, in fact, it does, but I am not sure. If a du'u is a predication, what is a predication? An assertion of a relationship between some arguments? What, then, are the arguments? If they are the things referred to in the sentence, it seems to me that {lo du'u la tom du la tomas} must be the very same predication as {lo du'u la tom du la tom}, since the things referred to in both are the same. Suppose you believe that Tom is rich. Then, you meet a beggar on the street named Thomas, and (because he's begging) come to believe that Thomas is poor. You don't realize that Tom and Thomas are the same person. You then say {mi na krici lo du'u la tomas ricfu}. Are you right or wrong? I want to ignore the weirdness that Lojban's context-sensitivity can give rise to (I think {ko'a broda ko'e} and {ko'a na broda ko'e} are not contradictory in suitable contexts). I think that if a du'u is a predication, the arguments of which are things referred to, you are wrong. You DO believe that Thomas is rich. Your problem is that you don't realize that the proposition that Thomas is rich and the proposition that Tom is rich are, in fact, the very same proposition (predication?). If you are not wrong, I think that a du'u must wrap up more than just the things referred to. And it's not just the particular reference assignments inside the du'u that matter—all names in all of my examples refer to the very same person. Rather it's the manner in which they're referred to that matters. If your utterance of {mi na krici lo du'u la tomas ricfu} is true, the fact that {la tomas} was used to refer to Tom, rather than, say {la tom}, must be wrapped up somehow in the du'u (and so the du'u must be more than just a predication as I understand "predication"). To unsubscribe from this list, send mail to lojban-list-request@lojban.org with the subject unsubscribe, or go to http://www.lojban.org/lsg2/, or if you're really stuck, send mail to secretary@lojban.org for help.