Skip to content
quotesby

About this quote

What does it mean?
Theories are never absolutely true but are accepted based on passing tests others fail.
In plain terms
Theories are tested against rivals but never proven truly.
What can you take from it?
Knowledge grows through comparison, not absolute proof.

Where it applies

  • scientific research
  • evaluating claims
  • education

Putting it to work

  • testing hypotheses
  • comparing models
  • seeking evidence

Questions to consider

  • Can anything ever be proven true?
  • How do you judge competing ideas?

Another view

Practical decisions often require treating theories as true.

More from Alfred Ayer

  1. No moral system can rest solely on authority.

    Permalink to quote #3
  2. It seems that I have spent my entire time trying to make life more rational and that it was all wasted effort.

    Permalink to quote #5
  3. If now I:say 'Stealing money is wrong,' I produce a sentence which has no factual meaning - that is, expresses no proposition which can be either true or false…

    Permalink to quote #2

Related quotes

  1. There is nothing more practical than a good theory.

    Leonid BrezhnevLeonid Brezhnev quote #1
  2. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in nu…

    William ThomsonWilliam Thomson quote #1
  3. 'Faith' is a fine invention When Gentlemen can see - But Microscopes are prudent In an Emergency.

    Emily DickinsonEmily Dickinson quote #3