display all the ideas for this combination of philosophers
4 ideas
| 5183 | Only tautologies can be certain; other propositions can only be probable [Ayer] |
| Full Idea: No proposition, other than a tautology, can possibly be anything more than a probable hypothesis. | |
| From: A.J. Ayer (Language,Truth and Logic [1936], Ch.1) | |
| A reaction: A nice clear empiricist rejection of all attempts to assert necessary truths about nature. This also seems to be a rejection of empiricist foundationalism. A problem case seems to be introspective observations, which seem irrefutable and obvious. |
| 19461 | Knowing I exist reveals nothing at all about my nature [Ayer] |
| Full Idea: To know that one exists is not to know anything about oneself any more than knowing that 'this' exists is knowing anything about 'this'. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii) | |
| A reaction: Descartes proceeds to define himself as a 'thinking thing', inferring that thinking is his essence. Ayer casts nice doubt on that. |
| 19459 | To say 'I am not thinking' must be false, but it might have been true, so it isn't self-contradictory [Ayer] |
| Full Idea: To say 'I am not thinking' is self-stultifying since if it is said intelligently it must be false: but it is not self-contradictory. The proof that it is not self-contradictory is that it might have been false. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii) | |
| A reaction: If it doesn't imply a contradiction, then it is not a necessary truth, which is what it is normally taken to be. Is 'This is a sentence' necessarily true? It might not have been one, if the rules of English syntax changed recently. |
| 19460 | 'I know I exist' has no counterevidence, so it may be meaningless [Ayer] |
| Full Idea: If there is no experience at all of finding out that one is not conscious, or that one does not exist, ..it is tempting to say that sentences like 'I exist', 'I am conscious', 'I know that I exist' do not express genuine propositions. | |
| From: A.J. Ayer (The Problem of Knowledge [1956], 2.iii) | |
| A reaction: This is, of course, an application of the somewhat discredited verification principle, but the fact that strictly speaking the principle has been sort of refuted does not mean that we should not take it seriously, and be influenced by it. |