9 ideas
3035 | Dialectic involves conversations with short questions and brief answers [Diog. Laertius] |
Full Idea: Dialectic is when men converse by putting short questions and giving brief answers to those who question them. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 3.1.52) |
8754 | Logic is dependent on mathematics, not the other way round [Heyting, by Shapiro] |
Full Idea: Heyting (the intuitionist pupil of Brouwer) said that 'logic is dependent on mathematics', not the other way round. | |
From: report of Arend Heyting (Intuitionism: an Introduction [1956]) by Stewart Shapiro - Thinking About Mathematics 7.3 | |
A reaction: To me, this claim makes logicism sound much more plausible, as I don't see how mathematics could get beyond basic counting without a capacity for logical thought. Logic runs much deeper, psychologically and metaphysically. |
1816 | Sceptics say demonstration depends on self-demonstrating things, or indemonstrable things [Diog. Laertius] |
Full Idea: Sceptics say that every demonstration depends on things which demonstrates themselves, or on things which can't be demonstrated. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 9.Py.11) | |
A reaction: This refers to two parts of Agrippa's Trilemma (the third being that demonstration could go on forever). He makes the first option sound very rationalist, rather than experiential. |
1819 | Scepticism has two dogmas: that nothing is definable, and every argument has an opposite argument [Diog. Laertius] |
Full Idea: Sceptics actually assert two dogmas: that nothing should be defined, and that every argument has an opposite argument. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 9.Py.11) |
3064 | When sceptics say that nothing is definable, or all arguments have an opposite, they are being dogmatic [Diog. Laertius] |
Full Idea: When sceptics say that they define nothing, and that every argument has an opposite argument, they here give a positive definition, and assert a positive dogma. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 9.11.11) |
3033 | Induction moves from some truths to similar ones, by contraries or consequents [Diog. Laertius] |
Full Idea: Induction is an argument which by means of some admitted truths establishes naturally other truths which resemble them; there are two kinds, one proceeding from contraries, the other from consequents. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 3.1.23) |
1838 | Cyrenaic pleasure is a motion, but Epicurean pleasure is a condition [Diog. Laertius] |
Full Idea: Cyrenaics place pleasure wholly in motion, whereas Epicurus admits it as a condition. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 10.28) | |
A reaction: Not a distinction we meet in modern discussions. Do events within the mind count as 'motion'? If so, these two agree. If not, I'd vote for Epicurus. |
1769 | Cynics believe that when a man wishes for nothing he is like the gods [Diog. Laertius] |
Full Idea: Cynics believe that when a man wishes for nothing he is like the gods. | |
From: Diogenes Laertius (Lives of Eminent Philosophers [c.250], 6.Men.3) |
7073 | I am a creative nothing, out of which I myself create everything [Stirner] |
Full Idea: I am not nothing in the sense of emptiness, but I am the creative nothing, the nothing out of which I myself as creator create everything. | |
From: Max Stirner (The Ego and Its Own [1844]), quoted by Simon Critchley - Continental Philosophy - V. Short Intro Ch.2 | |
A reaction: This appears to be the germ of the entire existentialist view, which gives a helpful gloss on the concept of 'nothing' - as the motivation for human creation, the vacuum in the mind that has to be filled. Call it 'creative boredom'. |