11 ideas
| 13949 | All models of Peano axioms are isomorphic, so the models all seem equally good for natural numbers [Cartwright,R on Peano] |
| Full Idea: Peano's axioms are categorical (any two models are isomorphic). Some conclude that the concept of natural number is adequately represented by them, but we cannot identify natural numbers with one rather than another of the isomorphic models. | |
| From: comment on Giuseppe Peano (Principles of Arithmetic, by a new method [1889], 11) by Richard Cartwright - Propositions 11 | |
| A reaction: This is a striking anticipation of Benacerraf's famous point about different set theory accounts of numbers, where all models seem to work equally well. Cartwright is saying that others have pointed this out. |
| 18113 | PA concerns any entities which satisfy the axioms [Peano, by Bostock] |
| Full Idea: Peano Arithmetic is about any system of entities that satisfies the Peano axioms. | |
| From: report of Giuseppe Peano (Principles of Arithmetic, by a new method [1889], 6.3) by David Bostock - Philosophy of Mathematics 6.3 | |
| A reaction: This doesn't sound like numbers in the fullest sense, since those should facilitate counting objects. '3' should mean that number of rose petals, and not just a position in a well-ordered series. |
| 17634 | Peano axioms not only support arithmetic, but are also fairly obvious [Peano, by Russell] |
| Full Idea: Peano's premises are recommended not only by the fact that arithmetic follows from them, but also by their inherent obviousness. | |
| From: report of Giuseppe Peano (Principles of Arithmetic, by a new method [1889], p.276) by Bertrand Russell - Regressive Method for Premises in Mathematics p.276 |
| 15653 | We can add Reflexion Principles to Peano Arithmetic, which assert its consistency or soundness [Halbach on Peano] |
| Full Idea: Peano Arithmetic cannot derive its own consistency from within itself. But it can be strengthened by adding this consistency statement or by stronger axioms (particularly ones partially expressing soundness). These are known as Reflexion Principles. | |
| From: comment on Giuseppe Peano (Principles of Arithmetic, by a new method [1889], 1.2) by Volker Halbach - Axiomatic Theories of Truth (2005 ver) 1.2 |
| 17635 | Arithmetic can have even simpler logical premises than the Peano Axioms [Russell on Peano] |
| Full Idea: Peano's premises are not the ultimate logical premises of arithmetic. Simpler premises and simpler primitive ideas are to be had by carrying our analysis on into symbolic logic. | |
| From: comment on Giuseppe Peano (Principles of Arithmetic, by a new method [1889], p.276) by Bertrand Russell - Regressive Method for Premises in Mathematics p.276 |
| 21982 | I only wish I had such eyes as to see Nobody! It's as much as I can do to see real people. [Carroll,L] |
| Full Idea: "I see nobody on the road," said Alice. - "I only wish I had such eyes," the King remarked. ..."To be able to see Nobody! ...Why, it's as much as I can do to see real people." | |
| From: Lewis Carroll (C.Dodgson) (Through the Looking Glass [1886], p.189), quoted by A.W. Moore - The Evolution of Modern Metaphysics 07.7 | |
| A reaction: [Moore quotes this, inevitably, in a chapter on Hegel] This may be a better candidate for the birth of philosophy of language than Frege's Groundwork. |
| 1457 | Morality requires a minimum commitment to the self [Rashdall] |
| Full Idea: A bare minimum of metaphysical belief about the self is found to be absolutely presupposed in the very idea of morality. | |
| From: Hastings Rashdall (Theory of Good and Evil [1907], II.III.I.4) | |
| A reaction: This may not be true of virtue theory, where we could have a whole creature which lacked any sense of personhood, but yet had clear virtues and vices in its social functioning. Even if choices are central to morality, that might not need a self. |
| 6674 | All moral judgements ultimately concern the value of ends [Rashdall] |
| Full Idea: All moral judgements are ultimately judgements as to the value of ends. | |
| From: Hastings Rashdall (Theory of Good and Evil [1907], VII.I) | |
| A reaction: I am increasingly struck by this, especially when observing that it is the great gap in Kant's theory. For some odd reason, he gives being rational the highest possible value. Why? Nietzsche is good on this. 'Eudaimonia' seems a good start, to me. |
| 6673 | Ideal Utilitarianism is teleological but non-hedonistic; the aim is an ideal end, which includes pleasure [Rashdall] |
| Full Idea: My view, called Ideal Utilitarianism, combines the utilitarian principle that Ethics must be teleological with a non-hedonistic view of ethical ends; actions are right or wrong as they produce an ideal end, which includes, but is not limited to, pleasure. | |
| From: Hastings Rashdall (Theory of Good and Evil [1907], VII.I) | |
| A reaction: I certainly think that if you are going to be a consequentialist, then it is ridiculous to limit the end to pleasure, as it is an 'open question' as to whether we judge pleasures or pains to be good or bad. I am fond of beauty, goodness and truth, myself. |
| 1458 | Conduct is only reasonable or unreasonable if the world is governed by reason [Rashdall] |
| Full Idea: Absolutely reasonable or unreasonable conduct could not exist in a world which was not itself the product of reason or governed by its dictates. | |
| From: Hastings Rashdall (Theory of Good and Evil [1907], II.III.I.4) |
| 1459 | Absolute moral ideals can't exist in human minds or material things, so their acceptance implies a greater Mind [Rashdall, by PG] |
| Full Idea: An absolute moral ideal cannot exist in material things, or in the minds of individual people, so belief in it requires belief in a Mind which contains the ideal and is its source. | |
| From: report of Hastings Rashdall (Theory of Good and Evil [1907], II.III.I.4) by PG - Db (ideas) |