89 ideas
7490 | Because of Darwin, wisdom as a definite attainable state has faded [Watson] |
7461 | The three key ideas are the soul, Europe, and the experiment [Watson] |
7464 | The big idea: imitation, the soul, experiments, God, heliocentric universe, evolution? [Watson] |
18835 | Logic doesn't have a metaphysical basis, but nor can logic give rise to the metaphysics [Rumfitt] |
7465 | Babylonian thinking used analogy, rather than deduction or induction [Watson] |
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] |
7466 | Mesopotamian numbers applied to specific things, and then became abstract [Watson] |
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] |
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] |
18820 | In English 'evidence' is a mass term, qualified by 'little' and 'more' [Rumfitt] |
20657 | There are 23 core brain functions, with known circuit, transmitters, genes and behaviour [Watson] |
20656 | Traditional ideas of the mind were weakened in the 1950s by mind-influencing drugs [Watson] |
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] |
20655 | Humans have been hunter-gatherers for 99.5% of their existence [Watson] |
7477 | Modern democracy is actually elective oligarchy [Watson] |
7810 | The 'Eumenides' of Aeschylus shows blood feuds replaced by law [Aeschylus, by Grayling] |
7478 | Greek philosophers invented the concept of 'nature' as their special subject [Watson] |
20650 | The Uncertainty Principle implies that cause and effect can't be measured [Watson] |
20649 | The interference of light through two slits confirmed that it is waves [Watson] |
20661 | Electrons rotate in hyrogen atoms 10^13 times per second [Watson] |
20647 | Quantum theory explains why nature is made up of units, such as elements [Watson] |
20654 | Only four particles are needed for matter: up and down quark, electron, electron-neutrino [Watson] |
20651 | The shape of molecules is important, as well as the atoms and their bonds [Watson] |
20652 | In 1828 the animal substance urea was manufactured from inorganic ingredients [Watson] |
20658 | Information is physical, and living can be seen as replicating and preserving information [Watson] |
7462 | DNA mutation suggests humans and chimpanzees diverged 6.6 million years ago [Watson] |
7470 | During the rise of civilizations, the main gods changed from female to male [Watson] |
7474 | Hinduism has no founder, or prophet, or creed, or ecclesiastical structure [Watson] |
7480 | Monotheism was a uniquely Israelite creation within the Middle East [Watson] |
7479 | Modern Judaism became stabilised in 200 CE [Watson] |
7481 | The Israelites may have asserted the uniqueness of Yahweh to justify land claims [Watson] |
7471 | The Gathas (hymns) of Zoroastrianism date from about 1000 BCE [Watson] |
7473 | Zoroaster conceived the afterlife, judgement, heaven and hell, and the devil [Watson] |
7484 | Jesus never intended to start a new religion [Watson] |
7483 | Paul's early writings mention few striking episodes from Jesus' life [Watson] |
7475 | Confucius revered the spiritual world, but not the supernatural, or a personal god, or the afterlife [Watson] |
7476 | Taoism aims at freedom from the world, the body, the mind, and nature [Watson] |
7463 | The three basic ingredients of religion are: the soul, seers or priests, and ritual [Watson] |
7468 | In ancient Athens the souls of the dead are received by the 'upper air' [Watson] |