Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: notesfiles Path: utzoo!watmath!clyde!burl!mgnetp!ihnp4!zehntel!hplabs!hp-pcd!hpfcla!hpfclo!jacob From: jacob@hpfclo.UUCP (jacob) Newsgroups: net.nlang Subject: Re: All men... Message-ID: <53300001@hpfclo.UUCP> Date: Tue, 7-Aug-84 11:52:00 EDT Article-I.D.: hpfclo.53300001 Posted: Tue Aug 7 11:52:00 1984 Date-Received: Mon, 6-Aug-84 01:07:00 EDT References: <237@siemens.UUCP> Organization: Hewlett-Packard - Fort Collins, CO Lines: 23 Nf-ID: #R:siemens:-23700:hpfclo:53300001:000:821 Nf-From: hpfclo!jacob Aug 2 07:52:00 1984 It might be "a perfectly acceptable statement," but it is an invalid deduction no matter which way to put it. Let's formalize the first statement ("A" = "for all", "E" = there exists): (A x)(Man(x) -> Die(x)) --> (E y)(Man(y) ^ Female(y)) Do you still claim it is a tautology? Same goes for the second, less ambiguous statement: (A x)(Human(x) -> Die(x)) --> (E y)(Man(y) ^ Female(y)) or, for that matter: (A x)(Human(x) -> Die(x)) --> (E y)(Human(y) ^ Female(y)) None of the above, independently, are true, so they are not valid deductions. The only reason the second formulation "feels better" is that we rely on knowledge that there are female humans. But that is the conclusion of the statement, so if we accept it as a premise, we don't even need to know if they die or not. Jacob Gore ihnp4!hpfcla!jacob