South Africa Flag logo

South African Skeptics

September 24, 2020, 06:53:21 AM
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
Go to mobile page.
News: Follow saskeptics on twitter.
   Skeptic Forum Board Index   Help Forum Rules Search GoogleTagged Login Register Chat Blogroll  
Pages: 1 2 [3]  All   Go Down
Author Topic:

Absolute certainty and universal truth.

 (Read 11414 times)
Description: Can we have 100% certainty that something always holds true?
0 Members and 1 Guest are viewing this topic.
Defollyant Iconoclast
Hero Member

Skeptical ability: +64/-9
Offline Offline

Posts: 3791

In solidarity with rwenzori: Κοπρος φανεται

« Reply #30 on: August 17, 2012, 15:58:49 PM »

Well yes, S' = PP is a tautology (i.e. trivially true) irrespective of the truth-value of P.  However, the meaning of S' (as opposed to its logical truth-value) is, as said, an awkward restatement of P.  If, moreover, P is an axiom or a theorem then P is true in addition to S'.

The more general case of S = PQ is discussed more fully in the post I linked to earlier.

The trick is in being fully aware of the distinctions between truth-value, logical validity and meaning.  A logical argument can be both true and logically valid (by being sufficiently general) but nonetheless without meaning because meaning will usually lie in particular instances of it.

Hero Member

Skeptical ability: +18/-2
Offline Offline

Posts: 1137

« Reply #31 on: August 17, 2012, 16:30:03 PM »

Thanks.  This was just an aside.

Have a nice weekend.  Wink
Pages: 1 2 [3]  All   Go Up

Jump to:  

Powered by SMF 1.1.11 | SMF © 2006-2009, Simple Machines LLC
Page created in 0.216 seconds with 23 sceptic queries.
Google visited last this page April 14, 2019, 08:39:44 AM
Privacy Policy