134 ideas
18450 | Philosophy has its own mode of death, by separating soul from body [Porphyry] |
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
18826 | 'True at a possibility' means necessarily true if what is said had obtained [Rumfitt] |
18803 | Semantics for propositions: 1) validity preserves truth 2) non-contradition 3) bivalence 4) truth tables [Rumfitt] |
12204 | The logic of metaphysical necessity is S5 [Rumfitt] |
18814 | 'Absolute necessity' would have to rest on S5 [Rumfitt] |
18798 | It is the second-order part of intuitionistic logic which actually negates some classical theorems [Rumfitt] |
18799 | Intuitionists can accept Double Negation Elimination for decidable propositions [Rumfitt] |
18830 | Most set theorists doubt bivalence for the Continuum Hypothesis, but still use classical logic [Rumfitt] |
18843 | The iterated conception of set requires continual increase in axiom strength [Rumfitt] |
18836 | A set may well not consist of its members; the empty set, for example, is a problem [Rumfitt] |
18837 | A set can be determinate, because of its concept, and still have vague membership [Rumfitt] |
18845 | If the totality of sets is not well-defined, there must be doubt about the Power Set Axiom [Rumfitt] |
11211 | If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt] |
18815 | Logic is higher-order laws which can expand the range of any sort of deduction [Rumfitt] |
9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
18804 | The case for classical logic rests on its rules, much more than on the Principle of Bivalence [Rumfitt] |
18805 | Classical logic rules cannot be proved, but various lines of attack can be repelled [Rumfitt] |
18827 | If truth-tables specify the connectives, classical logic must rely on Bivalence [Rumfitt] |
12195 | Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt] |
12199 | There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt] |
12201 | We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt] |
18813 | Logical consequence is a relation that can extended into further statements [Rumfitt] |
18808 | Normal deduction presupposes the Cut Law [Rumfitt] |
18840 | When faced with vague statements, Bivalence is not a compelling principle [Rumfitt] |
12194 | Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt] |
11210 | Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt] |
18802 | In specifying a logical constant, use of that constant is quite unavoidable [Rumfitt] |
11212 | The sense of a connective comes from primitively obvious rules of inference [Rumfitt] |
12198 | Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt] |
18800 | Introduction rules give deduction conditions, and Elimination says what can be deduced [Rumfitt] |
18809 | Logical truths are just the assumption-free by-products of logical rules [Rumfitt] |
18807 | Monotonicity means there is a guarantee, rather than mere inductive support [Rumfitt] |
18842 | Maybe an ordinal is a property of isomorphic well-ordered sets, and not itself a set [Rumfitt] |
17462 | A single object must not be counted twice, which needs knowledge of distinctness (negative identity) [Rumfitt] |
18834 | Infinitesimals do not stand in a determinate order relation to zero [Rumfitt] |
18846 | Cantor and Dedekind aimed to give analysis a foundation in set theory (rather than geometry) [Rumfitt] |
17461 | Some 'how many?' answers are not predications of a concept, like 'how many gallons?' [Rumfitt] |
18451 | The presence of the incorporeal is only known by certain kinds of disposition [Porphyry] |
15034 | Are genera and species real or conceptual? bodies or incorporeal? in sensibles or separate from them? [Porphyry] |
18459 | Diversity arises from the power of unity [Porphyry] |
9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |
18839 | An object that is not clearly red or orange can still be red-or-orange, which sweeps up problem cases [Rumfitt] |
18838 | The extension of a colour is decided by a concept's place in a network of contraries [Rumfitt] |
14532 | A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A] |
18816 | Metaphysical modalities respect the actual identities of things [Rumfitt] |
12193 | Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt] |
12200 | A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt] |
18825 | S5 is the logic of logical necessity [Rumfitt] |
12202 | Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt] |
18824 | Since possibilities are properties of the world, calling 'red' the determination of a determinable seems right [Rumfitt] |
18828 | If two possibilities can't share a determiner, they are incompatible [Rumfitt] |
12203 | If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt] |
18821 | Possibilities are like possible worlds, but not fully determinate or complete [Rumfitt] |
18831 | Medieval logicians said understanding A also involved understanding not-A [Rumfitt] |
18452 | Memory is not conserved images, but reproduction of previous thought [Porphyry] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
18453 | Intelligence is aware of itself, so the intelligence is both the thinker and the thought [Porphyry] |
18462 | The soul is everywhere and nowhere in the body, and must be its cause [Porphyry] |
18463 | Successful introspection reveals the substrate along with the object of thought [Porphyry] |
18458 | The soul is bound to matter by the force of its own disposition [Porphyry] |
18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
18464 | Justice is each person fulfilling his function [Porphyry] |
19956 | True goodness is political, and consists of love of and submission to the laws [Montesquieu] |
18448 | We should avoid the pleasures of love, or at least, should not enact our dreams [Porphyry] |
18444 | Civil virtues make us behave benevolently, and thereby unite citizens [Porphyry] |
18445 | Civil virtues control the passions, and make us conform to our nature [Porphyry] |
18446 | Purificatory virtues detach the soul completely from the passions [Porphyry] |
18447 | There are practical, purificatory, contemplative, and exemplary virtues [Porphyry] |
19961 | Primitive people would be too vulnerable and timid to attack anyone, so peace would reign [Montesquieu] |
19962 | Men do not desire to subjugate one another; domination is a complex and advanced idea [Montesquieu] |
19963 | People are drawn into society by needs, shared fears, pleasure, and knowledge [Montesquieu] |
20008 | People are guided by a multitude of influences, from which the spirit of a nation emerges [Montesquieu] |
19993 | In small republics citizens identify with the public good, and abuses are fewer [Montesquieu] |
19992 | In a large republic there is too much wealth for individuals to manage it [Montesquieu] |
20005 | The rich would never submit to a lottery deciding which part of their society should be slaves [Montesquieu] |
19995 | All states aim at preservation, and then have distinctive individual purposes [Montesquieu] |
19964 | The natural power of a father suggests rule by one person, but that authority can be spread [Montesquieu] |
19986 | Monarchies can act more quickly, because one person is in charge [Montesquieu] |
19972 | The nobility are an indispensable part of a monarchy [Montesquieu] |
19974 | Monarchs must not just have links to the people; they need a body which maintains the laws [Montesquieu] |
19976 | Ambition is good in a monarchy, because the monarch can always restrain it [Montesquieu] |
19978 | In monarchies, men's actions are judged by their grand appearance, not their virtues [Montesquieu] |
19985 | In a monarchy, the nobility must be hereditary, to bind them together [Montesquieu] |
19988 | A despot's agents must be given power, so they inevitably become corrupt [Montesquieu] |
19977 | Despotism and honour are incompatible, because honour scorns his power, and lives by rules [Montesquieu] |
20007 | Tyranny is either real violence, or the imposition of unpopular legislation [Montesquieu] |
19975 | Despots are always lazy and ignorant, so they always delegate their power to a vizier [Montesquieu] |
19989 | The will of a despot is an enigma, so magistrates can only follow their own will [Montesquieu] |
19970 | If the nobility is numerous, the senate is the artistocracy, and the nobles are a democracy [Montesquieu] |
19971 | Aristocracy is democratic if they resemble the people, but not if they resemble the monarch [Montesquieu] |
19984 | Great inequality between aristocrats and the rest is bad - and also among aristocrats themselves [Montesquieu] |
19980 | If a government is to be preserved, it must first be loved [Montesquieu] |
19996 | A government has a legislature, an international executive, and a domestic executive [Montesquieu] |
19997 | The judiciary must be separate from the legislature, to avoid arbitrary power [Montesquieu] |
19965 | The fundamental laws of a democracy decide who can vote [Montesquieu] |
19968 | It is basic to a democracy that the people themselves must name their ministers [Montesquieu] |
19969 | Voting should be public, so the lower classes can be influenced by the example of notable people [Montesquieu] |
19999 | All citizens (apart from the very humble poor) should choose their representatives [Montesquieu] |
19967 | In a democracy the people should manage themselves, and only delegate what they can't do [Montesquieu] |
19966 | A democratic assembly must have a fixed number, to see whether everyone has spoken [Montesquieu] |
19998 | If deputies represent people, they are accountable, but less so if they represent places [Montesquieu] |
20003 | Slaves are not members of the society, so no law can forbid them to run away [Montesquieu] |
20000 | Slavery is entirely bad; the master abandons the virtues, and they are pointless in the slave [Montesquieu] |
20006 | The demand for slavery is just the masters' demand for luxury [Montesquieu] |
20009 | Freedom of speech and writing, within the law, is essential to preserve liberty [Montesquieu] |
19994 | Freedom in society is ability to do what is right, and not having to do what is wrong [Montesquieu] |
19981 | No one even thinks of equality in monarchies and despotism; they all want superiority [Montesquieu] |
19991 | Equality is not command by everyone or no one, but command and obedience among equals [Montesquieu] |
19990 | Democracy is corrupted by lack of equality, or by extreme equality (between rulers and ruled) [Montesquieu] |
19983 | Democracies may sometimes need to restrict equality [Montesquieu] |
19982 | Some equality can be achieved by social categories, combined with taxes and poor relief [Montesquieu] |
19959 | Prior to positive laws there is natural equity, of obedience, gratitude, dependence and merit [Montesquieu] |
19960 | Sensation gives animals natural laws, but knowledge can make them break them [Montesquieu] |
20002 | The death penalty is permissible, because its victims enjoyed the protection of that law [Montesquieu] |
20010 | If religion teaches determinism, penalties must be severe; if free will, then that is different [Montesquieu] |
20001 | The only right victors have over captives is the protection of the former [Montesquieu] |
19973 | The clergy are essential to a monarchy, but dangerous in a republic [Montesquieu] |
19987 | Religion has the most influence in despotic states, and reinforces veneration for the ruler [Montesquieu] |
20011 | Religion can support the state when the law fails to do so [Montesquieu] |
20004 | French slavery was accepted because it was the best method of religious conversion [Montesquieu] |
19979 | In monarchies education ennobles people, and in despotisms it debases them [Montesquieu] |
19957 | Teaching is the best practice of the general virtue that leads us to love everyone [Montesquieu] |
18456 | Unified real existence is neither great nor small, though greatness and smallness participate in it [Porphyry] |
19958 | Laws are the necessary relations that derive from the nature of things [Montesquieu] |
18454 | Time is the circular movement of the soul [Porphyry] |
18455 | Some think time is seen at rest, as well as in movement [Porphyry] |
18460 | God is nowhere, and hence everywhere [Porphyry] |
18461 | Everything existing proceeds from divinity, and is within divinity [Porphyry] |
18449 | Nature binds or detaches body to soul, but soul itself joins and detaches soul from body [Porphyry] |
18457 | Individual souls are all connected, though distinct, and without dividing universal Soul [Porphyry] |