Full Text

logical truth


Subject Philosophy

DOI: 10.1111/b.9781405106795.2004.x


Extract

L ogic, epistemology A logical symbol or logical formula can be a logical truth because it is true under all interpretations . A statement or proposition is logically true if it is validly deduced in a logical system. In this sense, a logical truth is generally a theorem of a logical system. More often, we say that a statement is a logical truth because it is an instance of a valid logical form . For example, “A house cannot be both warm and not warm.” The logical form of this sentence is “not both p and nonp,” and it is thus in accord with the principle of noncontradiction. If a statement is logically true, then it is analytic and is necessarily true. On the contrary, if a statement violates a logically valid form, that is, if its logical form conflicts with some logical principle, it is logically false or a logical falsity. If a statement is logically false, it is necessarily false. Accounts of the kind of logical truth that depends upon the meaning of the expressions contained in a proposition have come under pressure from Quine 's rejection of the analytic-synthetic distinction and the notions of synonymy and meaning . Without reliance on meaning, a logical truth becomes any truth which can be obtained from a valid logical scheme. “A logical schema is valid if every sentence obtainable from it by substituting sentences for simple sentence is true. A logical ... log in or subscribe to read full text

Log In

You are not currently logged-in to Blackwell Reference Online

If your institution has a subscription, you can log in here:

 

     Forgotten your password?

Find out how to subscribe.

Your library does not have access to this title. Please contact your librarian to arrange access.


[ access key 0 : accessibility information including access key list ] [ access key 1 : home page ] [ access key 2 : skip navigation ] [ access key 6 : help ] [ access key 9 : contact us ] [ access key 0 : accessibility statement ]

Blackwell Publishing Home Page

Blackwell Reference Online ® is a Blackwell Publishing Inc. registered trademark
Technology partner: Semantico Ltd.

Blackwell Publishing and its licensors hold the copyright in all material held in Blackwell Reference Online. No material may be resold or published elsewhere without Blackwell Publishing's written consent, save as authorised by a licence with Blackwell Publishing or to the extent required by the applicable law.

Back to Top