160 ideas
23890 | For Plato true wisdom is supernatural [Plato, by Weil] |
3060 | Plato never mentions Democritus, and wished to burn his books [Plato, by Diog. Laertius] |
19807 | Both nature and reason require that everything has a cause [Rousseau] |
23891 | Two contradictories force us to find a relation which will correlate them [Plato, by Weil] |
9738 | Each line of a truth table is a model [Fitting/Mendelsohn] |
9727 | Modal logic adds □ (necessarily) and ◊ (possibly) to classical logic [Fitting/Mendelsohn] |
9726 | We let 'R' be the accessibility relation: xRy is read 'y is accessible from x' [Fitting/Mendelsohn] |
9737 | The symbol ||- is the 'forcing' relation; 'Γ ||- P' means that P is true in world Γ [Fitting/Mendelsohn] |
13136 | The prefix σ names a possible world, and σ.n names a world accessible from that one [Fitting/Mendelsohn] |
13727 | A 'constant' domain is the same for all worlds; 'varying' domains can be entirely separate [Fitting/Mendelsohn] |
9734 | Modern modal logic introduces 'accessibility', saying xRy means 'y is accessible from x' [Fitting/Mendelsohn] |
9736 | A 'model' is a frame plus specification of propositions true at worlds, written < G,R,||- > [Fitting/Mendelsohn] |
9735 | A 'frame' is a set G of possible worlds, with an accessibility relation R, written < G,R > [Fitting/Mendelsohn] |
9741 | Accessibility relations can be 'reflexive' (self-referring), 'transitive' (carries over), or 'symmetric' (mutual) [Fitting/Mendelsohn] |
13149 | S5: a) if n ◊X then kX b) if n ¬□X then k ¬X c) if n □X then k X d) if n ¬◊X then k ¬X [Fitting/Mendelsohn] |
13141 | Negation: if σ ¬¬X then σ X [Fitting/Mendelsohn] |
13138 | Disj: a) if σ ¬(X∨Y) then σ ¬X and σ ¬Y b) if σ X∨Y then σ X or σ Y [Fitting/Mendelsohn] |
13142 | Existential: a) if σ ◊X then σ.n X b) if σ ¬□X then σ.n ¬X [n is new] [Fitting/Mendelsohn] |
13144 | T reflexive: a) if σ □X then σ X b) if σ ¬◊X then σ ¬X [Fitting/Mendelsohn] |
13145 | D serial: a) if σ □X then σ ◊X b) if σ ¬◊X then σ ¬□X [Fitting/Mendelsohn] |
13146 | B symmetric: a) if σ.n □X then σ X b) if σ.n ¬◊X then σ ¬X [n occurs] [Fitting/Mendelsohn] |
13147 | 4 transitive: a) if σ □X then σ.n □X b) if σ ¬◊X then σ.n ¬◊X [n occurs] [Fitting/Mendelsohn] |
13148 | 4r rev-trans: a) if σ.n □X then σ □X b) if σ.n ¬◊X then σ ¬◊X [n occurs] [Fitting/Mendelsohn] |
9740 | If a proposition is possibly true in a world, it is true in some world accessible from that world [Fitting/Mendelsohn] |
9739 | If a proposition is necessarily true in a world, it is true in all worlds accessible from that world [Fitting/Mendelsohn] |
13137 | Conj: a) if σ X∧Y then σ X and σ Y b) if σ ¬(X∧Y) then σ ¬X or σ ¬Y [Fitting/Mendelsohn] |
13140 | Bicon: a)if σ(X↔Y) then σ(X→Y) and σ(Y→X) b) [not biconditional, one or other fails] [Fitting/Mendelsohn] |
13139 | Implic: a) if σ ¬(X→Y) then σ X and σ ¬Y b) if σ X→Y then σ ¬X or σ Y [Fitting/Mendelsohn] |
13143 | Universal: a) if σ ¬◊X then σ.m ¬X b) if σ □X then σ.m X [m exists] [Fitting/Mendelsohn] |
9742 | The system K has no accessibility conditions [Fitting/Mendelsohn] |
13114 | □P → P is not valid in D (Deontic Logic), since an obligatory action may be not performed [Fitting/Mendelsohn] |
9743 | The system D has the 'serial' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
9744 | The system T has the 'reflexive' conditon imposed on its accessibility relation [Fitting/Mendelsohn] |
9746 | The system K4 has the 'transitive' condition on its accessibility relation [Fitting/Mendelsohn] |
9745 | The system B has the 'reflexive' and 'symmetric' conditions on its accessibility relation [Fitting/Mendelsohn] |
9747 | The system S4 has the 'reflexive' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
9748 | System S5 has the 'reflexive', 'symmetric' and 'transitive' conditions on its accessibility relation [Fitting/Mendelsohn] |
9404 | Modality affects content, because P→◊P is valid, but ◊P→P isn't [Fitting/Mendelsohn] |
13112 | In epistemic logic knowers are logically omniscient, so they know that they know [Fitting/Mendelsohn] |
13111 | Read epistemic box as 'a knows/believes P' and diamond as 'for all a knows/believes, P' [Fitting/Mendelsohn] |
13113 | F: will sometime, P: was sometime, G: will always, H: was always [Fitting/Mendelsohn] |
13728 | The Barcan says nothing comes into existence; the Converse says nothing ceases; the pair imply stability [Fitting/Mendelsohn] |
13729 | The Barcan corresponds to anti-monotonicity, and the Converse to monotonicity [Fitting/Mendelsohn] |
9725 | 'Predicate abstraction' abstracts predicates from formulae, giving scope for constants and functions [Fitting/Mendelsohn] |
14502 | Plato's idea of 'structure' tends to be mathematically expressed [Plato, by Koslicki] |
17948 | Plato's Forms meant that the sophists only taught the appearance of wisdom and virtue [Plato, by Nehamas] |
3039 | When Diogenes said he could only see objects but not their forms, Plato said it was because he had eyes but no intellect [Plato, by Diog. Laertius] |
20906 | Platonists argue for the indivisible triangle-in-itself [Plato, by Aristotle] |
556 | If there is one Form for both the Form and its participants, they must have something in common [Aristotle on Plato] |
563 | If gods are like men, they are just eternal men; similarly, Forms must differ from particulars [Aristotle on Plato] |
557 | A Form is a cause of things only in the way that white mixed with white is a cause [Aristotle on Plato] |
565 | The Forms cannot be changeless if they are in changing things [Aristotle on Plato] |
9607 | The greatest discovery in human thought is Plato's discovery of abstract objects [Brown,JR on Plato] |
13263 | We can grasp whole things in science, because they have a mathematics and a teleology [Plato, by Koslicki] |
13261 | Plato sees an object's structure as expressible in mathematics [Plato, by Koslicki] |
13265 | Plato was less concerned than Aristotle with the source of unity in a complex object [Plato, by Koslicki] |
593 | Plato's holds that there are three substances: Forms, mathematical entities, and perceptible bodies [Plato, by Aristotle] |
13260 | Plato says wholes are either containers, or they're atomic, or they don't exist [Plato, by Koslicki] |
11237 | Only universals have essence [Plato, by Politis] |
11238 | Plato and Aristotle take essence to make a thing what it is [Plato, by Politis] |
13730 | The Indiscernibility of Identicals has been a big problem for modal logic [Fitting/Mendelsohn] |
13725 | □ must be sensitive as to whether it picks out an object by essential or by contingent properties [Fitting/Mendelsohn] |
13731 | Objects retain their possible properties across worlds, so a bundle theory of them seems best [Fitting/Mendelsohn] |
13726 | Counterpart relations are neither symmetric nor transitive, so there is no logic of equality for them [Fitting/Mendelsohn] |
17085 | A good explanation totally rules out the opposite explanation (so Forms are required) [Plato, by Ruben] |
1651 | Plato wanted to somehow control and purify the passions [Vlastos on Plato] |
3324 | Plato's whole philosophy may be based on being duped by reification - a figure of speech [Benardete,JA on Plato] |
7235 | Without freedom of will actions lack moral significance [Rousseau] |
7503 | Plato never refers to examining the conscience [Plato, by Foucault] |
2173 | As religion and convention collapsed, Plato sought morals not just in knowledge, but in the soul [Williams,B on Plato] |
9274 | Plato's legacy to European thought was the Good, the Beautiful and the True [Plato, by Gray] |
94 | Pleasure is better with the addition of intelligence, so pleasure is not the good [Plato, by Aristotle] |
17947 | Plato decided that the virtuous and happy life was the philosophical life [Plato, by Nehamas] |
6015 | Plato, unusually, said that theoretical and practical wisdom are inseparable [Plato, by Kraut] |
2912 | Plato is boring [Nietzsche on Plato] |
19791 | Natural mankind is too fragmented for states of peace, or of war and enmity [Rousseau] |
20501 | Rousseau assumes that laws need a people united by custom and tradition [Rousseau, by Wolff,J] |
7237 | The act of becoming 'a people' is the real foundation of society [Rousseau] |
19792 | To overcome obstacles, people must unite their forces into a single unified power [Rousseau] |
19812 | Human nature changes among a people, into a moral and partial existence [Rousseau] |
19814 | A state must be big enough to preserve itself, but small enough to be governable [Rousseau] |
19815 | Too much land is a struggle, producing defensive war; too little makes dependence, and offensive war [Rousseau] |
19822 | If the state enlarges, the creators of the general will become less individually powerful [Rousseau] |
19823 | If the population is larger, the government needs to be more powerful [Rousseau] |
7232 | Man is born free, and he is everywhere in chains [Rousseau] |
7234 | No man has any natural authority over his fellows [Rousseau] |
19816 | A state's purpose is liberty and equality - liberty for strength, and equality for liberty [Rousseau] |
7247 | The greatest social good comes down to freedom and equality [Rousseau] |
19838 | The measure of a successful state is increase in its population [Rousseau] |
19848 | The sovereignty does not appoint the leaders [Rousseau] |
20567 | Rousseau insists that popular sovereignty needs a means of expressing consent [Rousseau, by Oksala] |
19801 | Sovereignty is the exercise of the general will, which can never be delegated [Rousseau] |
19805 | Just as people control their limbs, the general-will state has total control of its members [Rousseau] |
19818 | Political laws are fundamental, as they firmly organise the state - but they could still be changed [Rousseau] |
19790 | Force can only dominate if it is seen as a right, and obedience as a duty [Rousseau] |
7233 | The social order is a sacred right, but based on covenants, not nature [Rousseau] |
19842 | The government is instituted by a law, not by a contract [Rousseau] |
7239 | The social pact is the total subjection of individuals to the general will [Rousseau] |
19793 | We need a protective association which unites forces, but retains individual freedom [Rousseau] |
7240 | To foreign powers a state is seen as a simple individual [Rousseau] |
19795 | The act of association commits citizens to the state, and the state to its citizens [Rousseau] |
19797 | Citizens must ultimately for forced to accept the general will (so freedom is compulsory!) [Rousseau] |
19796 | Individual citizens still retain a private will, which may be contrary to the general will [Rousseau] |
7244 | The general will is common interest; the will of all is the sum of individual desires [Rousseau] |
19802 | The general will is always right, but the will of all can err, because it includes private interests [Rousseau] |
19803 | If the state contains associations there are fewer opinions, undermining the general will [Rousseau] |
19804 | If a large knowledgeable population votes in isolation, their many choices will have good results [Rousseau] |
19808 | The general will changes its nature when it focuses on particulars [Rousseau] |
7246 | The general will is always good, but sometimes misunderstood [Rousseau] |
7250 | Laws are authentic acts of the general will [Rousseau] |
19844 | Assemblies must always confirm the form of government, and the current administration [Rousseau] |
19846 | The more unanimous the assembly, the stronger the general will becomes [Rousseau] |
19817 | Citizens should be independent of each other, and very dependent on the state [Rousseau] |
19840 | A citizen is a subject who is also sovereign [Rousseau] |
19839 | The flourishing of arts and letters is too much admired [Rousseau] |
19798 | Ancient monarchs were kings of peoples; modern monarchs more cleverly rule a land [Rousseau] |
19831 | The highest officers under a monarchy are normally useless; the public could choose much better [Rousseau] |
19833 | Hereditary monarchy is easier, but can lead to dreadful monarchs [Rousseau] |
19834 | Attempts to train future kings don't usually work, and the best have been unprepared [Rousseau] |
19829 | Natural aristocracy is primitive, and hereditary is dreadful, but elective aristocracy is best [Rousseau] |
7249 | Natural aristocracy is primitive, hereditary is bad, and elective aristocracy is the best [Rousseau] |
19830 | Large states need a nobility to fill the gap between a single prince and the people [Rousseau] |
19827 | Law makers and law implementers should be separate [Rousseau] |
19820 | The state has a legislature and an executive, just like the will and physical power in a person [Rousseau] |
19821 | I call the executive power the 'government', which is the 'prince' - a single person, or a group [Rousseau] |
19824 | Large populations needs stronger control, which means power should be concentrated [Rousseau] |
19826 | Democracy for small states, aristocracy for intermediate, monarchy for large [Rousseau] |
19837 | If inhabitants are widely dispersed, organising a revolt is much more difficult [Rousseau] |
19843 | The state is not bound to leave civil authority to its leaders [Rousseau] |
19825 | If the sovereign entrusts government to at least half the citizens, that is 'democracy' [Rousseau] |
19832 | Democratic elections are dangerous intervals in government [Rousseau] |
7243 | Silence of the people implies their consent [Rousseau] |
7251 | The English are actually slaves in between elections [Rousseau] |
7238 | Minorities only accept majority-voting because of a prior unanimous agreement [Rousseau] |
19828 | Democracy leads to internal strife, as people struggle to maintain or change ways of ruling [Rousseau] |
19835 | When ministers change the state changes, because they always reverse policies [Rousseau] |
19849 | In early theocracies the god was the king, and there were as many gods as nations [Rousseau] |
19841 | Sometimes full liberty is only possible at the expense of some complete enslavement [Rousseau] |
19847 | We can never assume that the son of a slave is a slave [Rousseau] |
7242 | Appetite alone is slavery, and self-prescribed laws are freedom [Rousseau] |
19800 | The social compact imposes conventional equality of rights on people who may start unequally [Rousseau] |
7248 | No citizen should be rich enough to buy another, and none so poor as forced to sell himself [Rousseau] |
19794 | If we all give up all of our rights together to the community, we will always support one another [Rousseau] |
7241 | In society man loses natural liberty, but gains a right to civil liberty and property [Rousseau] |
19806 | We alienate to society only what society needs - but society judges that, not us [Rousseau] |
19799 | Private property must always be subordinate to ownership by the whole community [Rousseau] |
19819 | The state ensures liberty, so civil law separates citizens, and binds them to the state [Rousseau] |
7245 | Natural justice, without sanctions, benefits the wicked, who exploit it [Rousseau] |
19809 | We accept the death penalty to prevent assassinations, so we must submit to it if necessary [Rousseau] |
19810 | A trial proves that a criminal has broken the social treaty, and is no longer a member of the state [Rousseau] |
19811 | Only people who are actually dangerous should be executed, even as an example [Rousseau] |
7236 | War gives no right to inflict more destruction than is necessary for victory [Rousseau] |
23607 | Wars are between States, not people, and the individuals are enemies by accident [Rousseau] |
19850 | By separating theological and political systems, Jesus caused divisions in the state [Rousseau] |
19852 | Civil religion needs one supreme god, an afterlife, justice, and the sanctity of the social contract [Rousseau] |
19853 | All religions should be tolerated, if they tolerate each other, and support citizenship [Rousseau] |
19851 | Every society has a religion as its base [Rousseau] |
19836 | The amount of taxation doesn't matter, if it quickly circulates back to the citizens [Rousseau] |
1526 | Almost everyone except Plato thinks that time could not have been generated [Plato, by Aristotle] |
7252 | A tyrant exploits Christians because they don't value this life, and are made to be slaves [Rousseau] |