171 ideas
7396 | Hobbes created English-language philosophy [Hobbes, by Tuck] |
17240 | Definitions are the first step in philosophy [Hobbes] |
6211 | Laughter is a sudden glory in realising the infirmity of others, or our own formerly [Hobbes] |
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
8014 | Resolve a complex into simple elements, then reconstruct the complex by using them [Hobbes, by MacIntyre] |
17237 | Definitions of things that are caused must express their manner of generation [Hobbes] |
17239 | Definition is resolution of names into successive genera, and finally the difference [Hobbes] |
17241 | A defined name should not appear in the definition [Hobbes] |
17242 | 'Petitio principii' is reusing the idea to be defined, in disguised words [Hobbes] |
18819 | The idea that there are unrecognised truths is basic to our concept of truth [Rumfitt] |
18915 | If facts are the truthmakers, they are not in the world [Engelbretsen] |
18919 | There are no 'falsifying' facts, only an absence of truthmakers [Engelbretsen] |
18826 | 'True at a possibility' means necessarily true if what is said had obtained [Rumfitt] |
18913 | Traditional term logic struggled to express relations [Engelbretsen] |
18907 | Term logic rests on negated terms or denial, and that propositions are tied pairs [Engelbretsen] |
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] |
17245 | A part of a part is a part of a whole [Hobbes] |
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] |
18912 | Was logic a branch of mathematics, or mathematics a branch of logic? [Engelbretsen] |
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] |
18922 | Logical syntax is actually close to surface linguistic form [Engelbretsen] |
18905 | Propositions can be analysed as pairs of terms glued together by predication [Engelbretsen] |
11212 | The sense of a connective comes from primitively obvious rules of inference [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] |
18908 | Standard logic only negates sentences, even via negated general terms or predicates [Engelbretsen] |
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] |
17258 | If we just say one, one, one, one, we don't know where we have got to [Hobbes] |
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] |
16789 | Only supernatural means could annihilate anything once it had being [Hobbes] |
18917 | Existence and nonexistence are characteristics of the world, not of objects [Engelbretsen] |
17253 | Change is nothing but movement [Hobbes] |
7559 | Every part of the universe is body, and non-body is not part of it [Hobbes] |
18916 | Facts are not in the world - they are properties of the world [Engelbretsen] |
18921 | Individuals are arranged in inclusion categories that match our semantics [Engelbretsen] |
16670 | Accidents are just modes of thinking about bodies [Hobbes] |
16621 | Accidents are not parts of bodies (like blood in a cloth); they have accidents as things have a size [Hobbes] |
16734 | The complete power of an event is just the aggregate of the qualities that produced it [Hobbes] |
17247 | The only generalities or universals are names or signs [Hobbes] |
14960 | Bodies are independent of thought, and coincide with part of space [Hobbes] |
17250 | If you separate the two places of one thing, you will also separate the thing [Hobbes] |
17249 | If you separated two things in the same place, you would also separate the places [Hobbes] |
17248 | If a whole body is moved, its parts must move with it [Hobbes] |
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] |
16620 | A chair is wood, and its shape is the form; it isn't 'compounded' of the matter and form [Hobbes] |
16790 | A body is always the same, whether the parts are together or dispersed [Hobbes] |
17244 | To make a whole, parts needn't be put together, but can be united in the mind [Hobbes] |
17233 | Particulars contain universal things [Hobbes] |
17246 | Some accidental features are permanent, unless the object perishes [Hobbes] |
17251 | The feature which picks out or names a thing is usually called its 'essence' [Hobbes] |
16622 | Essence is just an artificial word from logic, giving a way of thinking about substances [Hobbes] |
17257 | It is the same river if it has the same source, no matter what flows in it [Hobbes] |
12853 | Some individuate the ship by unity of matter, and others by unity of form [Hobbes] |
17256 | If a new ship were made of the discarded planks, would two ships be numerically the same? [Hobbes] |
16794 | As an infant, Socrates was not the same body, but he was the same human being [Hobbes] |
17255 | Two bodies differ when (at some time) you can say something of one you can't say of the other [Hobbes] |
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] |
6215 | 'Contingent' means that the cause is unperceived, not that there is no cause [Hobbes] |
16582 | We can imagine a point swelling and contracting - but not how this could be done [Hobbes] |
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] |
16638 | The qualities of the world are mere appearances; reality is the motions which cause them [Hobbes] |
2356 | Appearance and reality can be separated by mirrors and echoes [Hobbes] |
16688 | Evidence is conception, which is imagination, which proceeds from the senses [Hobbes] |
7405 | Experience can't prove universal truths [Hobbes] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
2357 | Dreams must be false because they seem absurd, but dreams don't see waking as absurd [Hobbes] |
17238 | Science aims to show causes and generation of things [Hobbes] |
17260 | Imagination is just weakened sensation [Hobbes] |
19373 | A 'conatus' is an initial motion, experienced by us as desire or aversion [Hobbes, by Arthur,R] |
2385 | If a man suddenly develops an intention of doing something, the cause is out of his control, not in his will [Hobbes] |
2358 | Freedom is absence of opposition to action; the idea of 'free will' is absurd [Hobbes] |
2384 | Those actions that follow immediately the last appetite are voluntary [Hobbes] |
6213 | A man cannot will to will, or will to will to will, so the idea of a voluntary will is absurd [Hobbes] |
6214 | Liberty and necessity are consistent, as when water freely flows, by necessity [Hobbes] |
6208 | Conceptions and apparitions are just motion in some internal substance of the head [Hobbes] |
2948 | Sensation is merely internal motion of the sentient being [Hobbes] |
23987 | The 'simple passions' are appetite, desire, love, aversion, hate, joy, and grief [Hobbes, by Goldie] |
17261 | Apart from pleasure and pain, the only emotions are appetite and aversion [Hobbes] |
17236 | Words are not for communication, but as marks for remembering what we have learned [Hobbes] |
18817 | We understand conditionals, but disagree over their truth-conditions [Rumfitt] |
18918 | Terms denote objects with properties, and statements denote the world with that property [Engelbretsen] |
18920 | 'Socrates is wise' denotes a sentence; 'that Socrates is wise' denotes a proposition [Engelbretsen] |
18829 | The truth grounds for 'not A' are the possibilities incompatible with truth grounds for A [Rumfitt] |
18906 | Negating a predicate term and denying its unnegated version are quite different [Engelbretsen] |
11214 | We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt] |
2362 | The will is just the last appetite before action [Hobbes] |
7408 | It is an error that reason should control the passions, which give right guidance on their own [Hobbes, by Tuck] |
2363 | Reason is usually general, but deliberation is of particulars [Hobbes] |
7407 | Good and evil are what please us; goodness and badness the powers causing them [Hobbes] |
2360 | 'Good' is just what we desire, and 'Evil' what we hate [Hobbes] |
7410 | Self-preservation is basic, and people judge differently about that, implying ethical relativism [Hobbes, by Tuck] |
2368 | Men's natural desires are no sin, and neither are their actions, until law makes it so [Hobbes] |
6209 | There is no absolute good, for even the goodness of God is goodness to us [Hobbes] |
2359 | Desire and love are the same, but in the desire the object is absent, and in love it is present [Hobbes] |
2370 | All voluntary acts aim at some good for the doer [Hobbes] |
7409 | Hobbes shifted from talk of 'the good' to talk of 'rights' [Hobbes, by Tuck] |
6210 | Life has no end (not even happiness), because we have desires, which presuppose a further end [Hobbes] |
2371 | A contract is a mutual transfer of rights [Hobbes] |
2372 | The person who performs first in a contract is said to 'merit' the return, and is owed it [Hobbes] |
8015 | Hobbes wants a contract to found morality, but shared values are needed to make a contract [MacIntyre on Hobbes] |
5337 | For Hobbes the Golden Rule concerns not doing things, whereas Jesus encourages active love [Hobbes, by Flanagan] |
2374 | In the violent state of nature, the merest suspicion is enough to justify breaking a contract [Hobbes] |
8016 | Fear of sanctions is the only motive for acceptance of authority that Hobbes can think of [MacIntyre on Hobbes] |
2375 | Suspicion will not destroy a contract, if there is a common power to enforce it [Hobbes] |
2377 | No one who admitted to not keeping contracts could ever be accepted as a citizen [Hobbes] |
2379 | If there is a good reason for breaking a contract, the same reason should have stopped the making of it [Hobbes] |
2373 | The first performer in a contract is handing himself over to an enemy [Hobbes] |
2382 | Someone who keeps all his contracts when others are breaking them is making himself a prey to others [Hobbes] |
2383 | Virtues are a means to peaceful, sociable and comfortable living [Hobbes] |
2376 | Injustice is the failure to keep a contract, and justice is the constant will to give what is owed [Hobbes] |
2367 | In time of war the life of man is solitary, poor, nasty, brutish and short [Hobbes] |
19764 | Hobbes attributed to savages the passions which arise in a law-bound society [Hobbes, by Rousseau] |
20566 | Hobbes says the people voluntarily give up their sovereignty, in a contract with a ruler [Hobbes, by Oksala] |
2366 | There is not enough difference between people for one to claim more benefit than another [Hobbes] |
20485 | Hobbes says people are roughly equal; Locke says there is no right to impose inequality [Hobbes, by Wolff,J] |
2369 | If we seek peace and defend ourselves, we must compromise on our rights [Hobbes] |
20484 | We should obey the laws of nature, provided other people are also obeying them [Hobbes, by Wolff,J] |
7573 | The legal positivism of Hobbes said law is just formal or procedural [Hobbes, by Jolley] |
2380 | Punishment should only be for reform or deterrence [Hobbes] |
23609 | I act justly if I follow my Prince in an apparently unjust war, and refusing to fight would be injustice [Hobbes] |
2361 | If fear of unknown powers is legal it is religion, if it is illegal it is superstition [Hobbes] |
6212 | Lust involves pleasure, and also the sense of power in pleasing others [Hobbes] |
16600 | Prime matter is body considered with mere size and extension, and potential [Hobbes] |
17252 | Acting on a body is either creating or destroying a property in it [Hobbes] |
17254 | An effect needs a sufficient and necessary cause [Hobbes] |
2364 | Causation is only observation of similar events following each other, with nothing visible in between [Hobbes] |
17235 | A cause is the complete sum of the features which necessitate the effect [Hobbes] |
17234 | Motion is losing one place and acquiring another [Hobbes] |
17259 | 'Force' is the quantity of movement imposed on something [Hobbes] |
17243 | Past times can't exist anywhere, apart from in our memories [Hobbes] |
7411 | The attributes of God just show our inability to conceive his nature [Hobbes] |
2365 | Religion is built on ignorance and misinterpretation of what is unknown or frightening [Hobbes] |
2378 | Belief in an afterlife is based on poorly founded gossip [Hobbes] |