6 ideas
| 16974 | The nature of each logical concept is given by a collection of inference rules [Correia] |
| Full Idea: The view presented here presupposes that each logical concept is associated with some fixed and well defined collection of rules of inference which characterize its basic logical nature. | |
| From: Fabrice Correia (On the Reduction of Necessity to Essence [2012], 4) | |
| A reaction: [He gives Fine's 'Senses of Essences' 57-8 as a source] He seems to have in mind natural deduction, where the rules are for the introduction and elimination of the concepts. |
| 16973 | Explain logical necessity by logical consequence, or the other way around? [Correia] |
| Full Idea: One view is that logical consequence is to be understood in terms of logical necessity (some proposition holds necessarily, if some group of other propositions holds). Alternatively, logical necessity is a logical consequence of the empty set. | |
| From: Fabrice Correia (On the Reduction of Necessity to Essence [2012], 3) | |
| A reaction: I think my Finean preference is for all necessities to have a 'necessitator', so logical necessity results from logic in some way, perhaps from logical consequence, or from the essences of the connectives and operators. |
| 22442 | If lies were ever acceptable, with would undermine all duties based on contract [Kant] |
| Full Idea: Truthfulness is a duty that must be regarded as the basis of all duties to be grounded on a contract, the law of which is made uncertain and useless if even the least exception to it is admitted. | |
| From: Immanuel Kant (On a supposed right to lie [1797], p.30) | |
| A reaction: Should we keep contracts which are made by means of deception and coercion? Where could such absolute authority for contracts come from? Do contracts and treaties tend to lapse after a long period of time? |
| 22441 | The law will protect you if you tell a truth which results in murder [Kant] |
| Full Idea: If you have by a lie prevented someone bent on murder from committing the deed, then you are legally accountable for all the consequences that might arise from it. But if you keep strictly to the truth, then public justice can hold nothing against you. | |
| From: Immanuel Kant (On a supposed right to lie [1797], p.29) | |
| A reaction: Shocking, from a supposedly great thinker. Cowardly hiding behind a perverse law. What would Kant do if the law were changed, to condemn someone who told a truth which would probably lead to a murder? Would he accept a jail sentence? |
| 13304 | Learned men gain more in one day than others do in a lifetime [Posidonius] |
| Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes. | |
| From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078 | |
| A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book. |
| 20820 | Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus] |
| Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness. | |
| From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42 | |
| A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them. |