42 ideas
23247 | The need to act produces consciousness, and practical reason is the root of all reason [Fichte] |
23232 | Sufficient reason makes the transition from the particular to the general [Fichte] |
10775 | The axiom of choice now seems acceptable and obvious (if it is meaningful) [Tharp] |
10766 | Logic is either for demonstration, or for characterizing structures [Tharp] |
10767 | Elementary logic is complete, but cannot capture mathematics [Tharp] |
10769 | Second-order logic isn't provable, but will express set-theory and classic problems [Tharp] |
10762 | In sentential logic there is a simple proof that all truth functions can be reduced to 'not' and 'and' [Tharp] |
10776 | The main quantifiers extend 'and' and 'or' to infinite domains [Tharp] |
10774 | There are at least five unorthodox quantifiers that could be used [Tharp] |
10777 | Skolem mistakenly inferred that Cantor's conceptions were illusory [Tharp] |
10773 | The Löwenheim-Skolem property is a limitation (e.g. can't say there are uncountably many reals) [Tharp] |
10765 | Soundness would seem to be an essential requirement of a proof procedure [Tharp] |
10763 | Completeness and compactness together give axiomatizability [Tharp] |
10770 | If completeness fails there is no algorithm to list the valid formulas [Tharp] |
10771 | Compactness is important for major theories which have infinitely many axioms [Tharp] |
10772 | Compactness blocks infinite expansion, and admits non-standard models [Tharp] |
10764 | A complete logic has an effective enumeration of the valid formulas [Tharp] |
10768 | Effective enumeration might be proved but not specified, so it won't guarantee knowledge [Tharp] |
23227 | Each object has a precise number of properties, each to a precise degree [Fichte] |
23228 | The principle of activity and generation is found in a self-moving basic force [Fichte] |
23241 | I am myself, but not the external object; so I only sense myself, and not the object [Fichte] |
21966 | Self-consciousness is the basis of knowledge, and knowing something is knowing myself [Fichte] |
21967 | There is nothing to say about anything which is outside my consciousness [Fichte] |
21969 | Awareness of reality comes from the free activity of consciousness [Fichte] |
23231 | I immediately know myself, and anything beyond that is an inference [Fichte] |
23246 | Faith is not knowledge; it is a decision of the will [Fichte] |
23245 | Knowledge can't be its own foundation; there has to be regress of higher and higher authorities [Fichte] |
23242 | Consciousness has two parts, passively receiving sensation, and actively causing productions [Fichte] |
23240 | We can't know by sight or hearing without realising that we are doing so [Fichte] |
23243 | Consciousness of external things is always accompanied by an unnoticed consciousness of self [Fichte] |
23244 | Forming purposes is absolutely free, and produces something from nothing [Fichte] |
23237 | The capacity for freedom is above the laws of nature, with its own power of purpose and will [Fichte] |
23235 | I want independent control of the fundamental cause of my decisions [Fichte] |
23230 | Nature contains a fundamental force of thought [Fichte] |
23233 | The will is awareness of one of our inner natural forces [Fichte] |
23234 | I cannot change the nature which has been determined for me [Fichte] |
23239 | The self is, apart from outward behaviour, a drive in your nature [Fichte] |
23238 | If life lacks love it becomes destruction [Fichte] |
23236 | Freedom means making yourself become true to your essential nature [Fichte] |
13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
23229 | Nature is wholly interconnected, and the tiniest change affects everything [Fichte] |
20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |