84 ideas
6200 | Wisdom is knowing the highest good, and conforming the will to it [Kant] |
13466 | We are all post-Kantians, because he set the current agenda for philosophy [Hart,WD] |
6207 | What fills me with awe are the starry heavens above me and the moral law within me [Kant] |
13477 | The problems are the monuments of philosophy [Hart,WD] |
6184 | Consistency is the highest obligation of a philosopher [Kant] |
6203 | Metaphysics is just a priori universal principles of physics [Kant] |
13515 | To study abstract problems, some knowledge of set theory is essential [Hart,WD] |
13469 | Tarski showed how we could have a correspondence theory of truth, without using 'facts' [Hart,WD] |
13504 | Truth for sentences is satisfaction of formulae; for sentences, either all sequences satisfy it (true) or none do [Hart,WD] |
13503 | A first-order language has an infinity of T-sentences, which cannot add up to a definition of truth [Hart,WD] |
13500 | Conditional Proof: infer a conditional, if the consequent can be deduced from the antecedent [Hart,WD] |
13502 | ∃y... is read as 'There exists an individual, call it y, such that...', and not 'There exists a y such that...' [Hart,WD] |
13456 | Set theory articulates the concept of order (through relations) [Hart,WD] |
13497 | Nowadays ZFC and NBG are the set theories; types are dead, and NF is only useful for the whole universe [Hart,WD] |
13443 | ∈ relates across layers, while ⊆ relates within layers [Hart,WD] |
13442 | Without the empty set we could not form a∩b without checking that a and b meet [Hart,WD] |
13493 | In the modern view, foundation is the heart of the way to do set theory [Hart,WD] |
13495 | Foundation Axiom: an nonempty set has a member disjoint from it [Hart,WD] |
13461 | We can choose from finite and evident sets, but not from infinite opaque ones [Hart,WD] |
13462 | With the Axiom of Choice every set can be well-ordered [Hart,WD] |
13516 | If we accept that V=L, it seems to settle all the open questions of set theory [Hart,WD] |
13441 | Naïve set theory has trouble with comprehension, the claim that every predicate has an extension [Hart,WD] |
13494 | The iterative conception may not be necessary, and may have fixed points or infinitely descending chains [Hart,WD] |
13457 | A 'partial ordering' is irreflexive and transitive; the sets are ordered, but not the subsets [Hart,WD] |
13458 | A partial ordering becomes 'total' if any two members of its field are comparable [Hart,WD] |
13460 | 'Well-ordering' must have a least member, so it does the natural numbers but not the integers [Hart,WD] |
13490 | Von Neumann defines α<β as α∈β [Hart,WD] |
13481 | Maybe sets should be rethought in terms of the even more basic categories [Hart,WD] |
13506 | The universal quantifier can't really mean 'all', because there is no universal set [Hart,WD] |
13512 | Modern model theory begins with the proof of Los's Conjecture in 1962 [Hart,WD] |
13505 | Model theory studies how set theory can model sets of sentences [Hart,WD] |
13511 | Model theory is mostly confined to first-order theories [Hart,WD] |
13513 | Models are ways the world might be from a first-order point of view [Hart,WD] |
13496 | First-order logic is 'compact': consequences of a set are consequences of a finite subset [Hart,WD] |
13484 | Berry's Paradox: we succeed in referring to a number, with a term which says we can't do that [Hart,WD] |
13482 | The Burali-Forti paradox is a crisis for Cantor's ordinals [Hart,WD] |
13507 | The machinery used to solve the Liar can be rejigged to produce a new Liar [Hart,WD] |
13459 | The less-than relation < well-orders, and partially orders, and totally orders the ordinal numbers [Hart,WD] |
13491 | The axiom of infinity with separation gives a least limit ordinal ω [Hart,WD] |
13463 | There are at least as many infinite cardinals as transfinite ordinals (because they will map) [Hart,WD] |
13492 | Von Neumann's ordinals generalise into the transfinite better, because Zermelo's ω is a singleton [Hart,WD] |
13446 | 19th century arithmetization of analysis isolated the real numbers from geometry [Hart,WD] |
13509 | We can establish truths about infinite numbers by means of induction [Hart,WD] |
13474 | Euclid has a unique parallel, spherical geometry has none, and saddle geometry has several [Hart,WD] |
13471 | Mathematics makes existence claims, but philosophers usually say those are never analytic [Hart,WD] |
5500 | Biologists see many organic levels, 'abstract' if seen from below, 'structural' if seen from above [Lycan] |
13488 | Mass words do not have plurals, or numerical adjectives, or use 'fewer' [Hart,WD] |
5494 | 'Lightning is electric discharge' and 'Phosphorus is Venus' are synthetic a posteriori identities [Lycan] |
6181 | Necessity cannot be extracted from an empirical proposition [Kant] |
13480 | Fregean self-evidence is an intrinsic property of basic truths, rules and definitions [Hart,WD] |
13476 | The failure of key assumptions in geometry, mereology and set theory throw doubt on the a priori [Hart,WD] |
5496 | Functionalism has three linked levels: physical, functional, and mental [Lycan] |
5499 | A mental state is a functional realisation of a brain state when it serves the purpose of the organism [Lycan] |
13475 | The Fregean concept of GREEN is a function assigning true to green things, and false to the rest [Hart,WD] |
6183 | Can pure reason determine the will, or are empirical conditions relevant? [Kant] |
6191 | The will is the faculty of purposes, which guide desires according to principles [Kant] |
6190 | The sole objects of practical reason are the good and the evil [Kant] |
18235 | Only human reason can confer value on our choices [Kant, by Korsgaard] |
6196 | People cannot come to morality through feeling, because morality must not be sensuous [Kant] |
18675 | Kant may rate two things as finally valuable: having a good will, and deserving happiness [Orsi on Kant] |
22007 | An autonomous agent has dignity [Würde], which has absolute worth [Kant, by Pinkard] |
18234 | The good will is unconditionally good, because it is the only possible source of value [Kant, by Korsgaard] |
6192 | Good or evil cannot be a thing, but only a maxim of action, making the person good or evil [Kant] |
6197 | Morality involves duty and respect for law, not love of the outcome [Kant] |
6193 | Our happiness is all that matters, not as a sensation, but as satisfaction with our whole existence [Kant] |
1452 | Happiness is the condition of a rational being for whom everything goes as they wish [Kant] |
1454 | Morality is not about making ourselves happy, but about being worthy of happiness [Kant] |
6194 | The highest worth for human beings lies in dispositions, not just actions [Kant] |
6198 | Virtue is the supreme state of our pursuit of happiness, and so is supreme good [Kant] |
1456 | Moral law is holy, and the best we can do is achieve virtue through respect for the law [Kant] |
6185 | No one would lend money unless a universal law made it secure, even after death [Kant] |
6187 | Universality determines the will, and hence extends self-love into altruism [Kant] |
6201 | Everyone (even God) must treat rational beings as ends in themselves, and not just as means [Kant] |
6186 | A holy will is incapable of any maxims which conflict with the moral law [Kant] |
6195 | Reason cannot solve the problem of why a law should motivate the will [Kant] |
6188 | A permanent natural order could not universalise a rule permitting suicide [Kant] |
5501 | People are trying to explain biological teleology in naturalistic causal terms [Lycan] |
6199 | Obligation does not rest on the existence of God, but on the autonomy of reason [Kant] |
1453 | We have to postulate something outside nature which makes happiness coincide with morality [Kant] |
1455 | Belief in justice requires belief in a place for justice (heaven), a time (eternity), and a cause (God) [Kant, by PG] |
6205 | To know if this world must have been created by God, we would need to know all other possible worlds [Kant] |
6204 | Using God to explain nature is referring to something inconceivable to explain what is in front of you [Kant] |
6206 | From our limited knowledge we can infer great virtues in God, but not ultimate ones [Kant] |
6202 | In all naturalistic concepts of God, if you remove the human qualities there is nothing left [Kant] |