18 ideas
2922 | All intelligent Romans were Epicureans [Nietzsche] |
Full Idea: Every mind of any account in the Roman Empire was an Epicurean. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 58) |
23520 | Truth has had to be fought for, and normal life must be sacrificed to achieve it [Nietzsche] |
Full Idea: Truth has had to be fought for every step of the way, almost everything else dear to our hearts, on which our love and our trust in life depend, has had to be sacrificed to it. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 50) | |
A reaction: This, in one of his final works, seems to contradict every idea that Nietzsche is the high priest of relativism about truth. He (and Foucault) and interested in the social role of truth, but are not so daft as to reject its possibility. |
2914 | One must never ask whether truth is useful [Nietzsche] |
Full Idea: One must never ask whether truth is useful. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], Fore) |
11022 | Gentzen introduced a natural deduction calculus (NK) in 1934 [Gentzen, by Read] |
Full Idea: Gentzen introduced a natural deduction calculus (NK) in 1934. | |
From: report of Gerhard Gentzen (works [1938]) by Stephen Read - Thinking About Logic Ch.8 |
11065 | The inferential role of a logical constant constitutes its meaning [Gentzen, by Hanna] |
Full Idea: Gentzen argued that the inferential role of a logical constant constitutes its meaning. | |
From: report of Gerhard Gentzen (works [1938]) by Robert Hanna - Rationality and Logic 5.3 | |
A reaction: Possibly inspired by Wittgenstein's theory of meaning as use? This idea was the target of Prior's famous connective 'tonk', which has the role of implying anything you like, proving sentences which are not logical consequences. |
11023 | The logical connectives are 'defined' by their introduction rules [Gentzen] |
Full Idea: The introduction rules represent, as it were, the 'definitions' of the symbols concerned, and the elimination rules are no more, in the final analysis, than the consequences of these definitions. | |
From: Gerhard Gentzen (works [1938]), quoted by Stephen Read - Thinking About Logic Ch.8 | |
A reaction: If an introduction-rule (or a truth table) were taken as fixed and beyond dispute, then it would have the status of a definition, since there would be nothing else to appeal to. So is there anything else to appeal to here? |
11213 | Each logical symbol has an 'introduction' rule to define it, and hence an 'elimination' rule [Gentzen] |
Full Idea: To every logical symbol there belongs precisely one inference figure which 'introduces' the symbol ..and one which 'eliminates' it. The introductions represent the 'definitions' of the symbols concerned, and eliminations are consequences of these. | |
From: Gerhard Gentzen (works [1938], II.5.13), quoted by Ian Rumfitt - "Yes" and "No" III | |
A reaction: [1935 paper] This passage is famous, in laying down the basics of natural deduction systems of logic (ones using only rules, and avoiding axioms). Rumfitt questions whether Gentzen's account gives the sense of the connectives. |
10067 | Gentzen proved the consistency of arithmetic from assumptions beyond arithmetic [Gentzen, by Musgrave] |
Full Idea: Gentzen proved the consistency of arithmetic from assumptions which transcend arithmetic. | |
From: report of Gerhard Gentzen (works [1938]) by Alan Musgrave - Logicism Revisited §5 | |
A reaction: This does not contradict Gödel's famous result, but reinforces it. The interesting question is what assumptions Gentzen felt he had to make. |
468 | Musical performance can reveal a range of virtues [Damon of Ath.] |
Full Idea: In singing and playing the lyre, a boy will be likely to reveal not only courage and moderation, but also justice. | |
From: Damon (fragments/reports [c.460 BCE], B4), quoted by (who?) - where? |
2921 | Philosophy grasps the limits of human reason, and values are beyond it [Nietzsche] |
Full Idea: All the supreme problems of value are beyond human reason. To grasp the limits of human reason, only this is philosophy. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 55) | |
A reaction: The single most powerful idea in the writings of Nietzsche. Reason and truth are values. Why do we value philosophy? There is no escaping Nietzsche's question. |
20138 | Christianity is at war with the higher type of man, and excommunicates his basic instincts [Nietzsche] |
Full Idea: Christianity has waged a war to the death against the higher type of man, it has excommunicated all the fundamental instincts of this type. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 05) | |
A reaction: It seems rather insulting to say that the finest and most dedicated altruism practised by the most admirable Christians is the expression of a 'lower' instinct. |
20375 | Virtues must be highly personal; if not, it is merely respect for a concept [Nietzsche] |
Full Idea: A virtue has to be our invention, our most personal defence and necessity: in any other sense it is merely a danger. What does not condition our life harms it: a virtue merely from a feeling of respect for the concept 'virtue', as Kant desires it, is harm | |
From: Friedrich Nietzsche (The Anti-Christ [1889], §11) | |
A reaction: Presumably he sees virtue as the cutting edge of stiffling conventional morality. I'm a bit nervous about embracing highly personal virtues, partly because they might isolate me from my community. I ain't no übermensch. |
2915 | Each person should devise his own virtues and categorical imperative [Nietzsche] |
Full Idea: Each one of us should devise his own virtue, his own categorical imperative. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 11) |
2920 | A God who cures us of a head cold at the right moment is a total absurdity [Nietzsche] |
Full Idea: A God who cures a headcold for us at the right moment is so absurd a God he would have to be abolished even if he existed. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 52) |
2917 | Christianity is a revolt of things crawling on the ground against elevated things [Nietzsche] |
Full Idea: Christianity is a revolt of everything which crawls along the ground against everything which is elevated. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 43) |
2918 | The story in Genesis is the story of God's fear of science [Nietzsche] |
Full Idea: Has the famous story which stands at the beginning of the Bible really been understood - the story of God's mortal terror of science? | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 48) |
2919 | 'Faith' means not wanting to know what is true [Nietzsche] |
Full Idea: 'Faith' means not wanting to know what is true. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 52) |
2916 | The great lie of immortality destroys rationality and natural instinct [Nietzsche] |
Full Idea: The great lie of personal immortality destroys all rationality, all naturalness of instinct. | |
From: Friedrich Nietzsche (The Anti-Christ [1889], 43) |