74 ideas
| 125 | Is a gifted philosopher unmanly if he avoids the strife of the communal world? [Plato] |
| 12274 | Begin examination with basics, and subdivide till you can go no further [Aristotle] |
| 12260 | Dialectic starts from generally accepted opinions [Aristotle] |
| 1654 | In "Gorgias" Socrates is confident that his 'elenchus' will decide moral truth [Vlastos on Plato] |
| 4321 | We should test one another, by asking and answering questions [Plato] |
| 12291 | There can't be one definition of two things, or two definitions of the same thing [Aristotle] |
| 12292 | Definitions are easily destroyed, since they can contain very many assertions [Aristotle] |
| 12283 | In definitions the first term to be assigned ought to be the genus [Aristotle] |
| 12272 | We describe the essence of a particular thing by means of its differentiae [Aristotle] |
| 12279 | The differentia indicate the qualities, but not the essence [Aristotle] |
| 12289 | The genera and the differentiae are part of the essence [Aristotle] |
| 12261 | Differentia are generic, and belong with genus [Aristotle] |
| 12263 | 'Genus' is part of the essence shared among several things [Aristotle] |
| 12285 | The definition is peculiar to one thing, not common to many [Aristotle] |
| 18951 | For scientific purposes there is a precise concept of 'true-in-L', using set theory [Putnam] |
| 18953 | Modern notation frees us from Aristotle's restriction of only using two class-names in premises [Putnam] |
| 18949 | The universal syllogism is now expressed as the transitivity of subclasses [Putnam] |
| 18952 | '⊃' ('if...then') is used with the definition 'Px ⊃ Qx' is short for '¬(Px & ¬Qx)' [Putnam] |
| 18958 | In type theory, 'x ∈ y' is well defined only if x and y are of the appropriate type [Putnam] |
| 18954 | Before the late 19th century logic was trivialised by not dealing with relations [Putnam] |
| 18956 | Asserting first-order validity implicitly involves second-order reference to classes [Putnam] |
| 18962 | Unfashionably, I think logic has an empirical foundation [Putnam] |
| 18961 | We can identify functions with certain sets - or identify sets with certain functions [Putnam] |
| 18955 | Having a valid form doesn't ensure truth, as it may be meaningless [Putnam] |
| 11261 | Puzzles arise when reasoning seems equal on both sides [Aristotle] |
| 12273 | Unit is the starting point of number [Aristotle] |
| 18959 | Sets larger than the continuum should be studied in an 'if-then' spirit [Putnam] |
| 12267 | There are ten categories: essence, quantity, quality, relation, place, time, position, state, activity, passivity [Aristotle] |
| 12282 | An individual property has to exist (in past, present or future) [Aristotle] |
| 12264 | An 'accident' is something which may possibly either belong or not belong to a thing [Aristotle] |
| 18957 | Nominalism only makes sense if it is materialist [Putnam] |
| 18950 | Physics is full of non-physical entities, such as space-vectors [Putnam] |
| 12280 | Genus gives the essence better than the differentiae do [Aristotle] |
| 13269 | In the case of a house the parts can exist without the whole, so parts are not the whole [Aristotle] |
| 12284 | Everything that is has one single essence [Aristotle] |
| 12262 | An 'idion' belongs uniquely to a thing, but is not part of its essence [Aristotle] |
| 12290 | Destruction is dissolution of essence [Aristotle] |
| 12286 | If two things are the same, they must have the same source and origin [Aristotle] |
| 12266 | 'Same' is mainly for names or definitions, but also for propria, and for accidents [Aristotle] |
| 12287 | Two identical things have the same accidents, they are the same; if the accidents differ, they're different [Aristotle] |
| 12288 | Numerical sameness and generic sameness are not the same [Aristotle] |
| 12259 | Reasoning is when some results follow necessarily from certain claims [Aristotle] |
| 18960 | Most predictions are uninteresting, and are only sought in order to confirm a theory [Putnam] |
| 12271 | Induction is the progress from particulars to universals [Aristotle] |
| 12293 | We say 'so in cases of this kind', but how do you decide what is 'of this kind'? [Aristotle] |
| 114 | Rhetoric can produce conviction, but not educate people about right and wrong [Plato] |
| 116 | Rhetoric is irrational about its means and its ends [Plato] |
| 135 | All activity aims at the good [Plato] |
| 122 | Moral rules are made by the weak members of humanity [Plato] |
| 139 | A good person is bound to act well, and this brings happiness [Plato] |
| 128 | Is it natural to simply indulge our selfish desires? [Plato] |
| 4322 | In slaking our thirst the goodness of the action and the pleasure are clearly separate [Plato] |
| 136 | Good should be the aim of pleasant activity, not the other way round [Plato] |
| 134 | Good and bad people seem to experience equal amounts of pleasure and pain [Plato] |
| 4319 | In a fool's mind desire is like a leaky jar, insatiable in its desires, and order and contentment are better [Plato] |
| 132 | If happiness is the satisfaction of desires, then a life of scratching itches should be happiness [Plato] |
| 130 | Is the happiest state one of sensual, self-indulgent freedom? [Plato] |
| 120 | Should we avoid evil because it will bring us bad consequences? [Plato] |
| 118 | I would rather be a victim of crime than a criminal [Plato] |
| 12277 | Friendship is preferable to money, since its excess is preferable [Aristotle] |
| 12276 | Justice and self-control are better than courage, because they are always useful [Aristotle] |
| 131 | If absence of desire is happiness, then nothing is happier than a stone or a corpse [Plato] |
| 140 | Self-indulgent desire makes friendship impossible, because it makes a person incapable of co-operation [Plato] |
| 119 | A criminal is worse off if he avoids punishment [Plato] |
| 129 | Do most people praise self-discipline and justice because they are too timid to gain their own pleasure? [Plato] |
| 4320 | The popular view is that health is first, good looks second, and honest wealth third [Plato] |
| 12275 | We value friendship just for its own sake [Aristotle] |
| 12281 | Man is intrinsically a civilized animal [Aristotle] |
| 137 | As with other things, a good state is organised and orderly [Plato] |
| 141 | A good citizen won't be passive, but will redirect the needs of the state [Plato] |
| 123 | Do most people like equality because they are second-rate? [Plato] |
| 124 | Does nature imply that it is right for better people to have greater benefits? [Plato] |
| 12265 | All water is the same, because of a certain similarity [Aristotle] |
| 12278 | 'Being' and 'oneness' are predicated of everything which exists [Aristotle] |