20 ideas
| 5893 | A wise man has integrity, firmness of will, nobility, consistency, sobriety, patience [Cicero] |
| Full Idea: The wise man does nothing of which he can repent, nothing against his will, does everything nobly, consistently, soberly, rightly, not looking forward to anything as bound to come, is not astonished at any novel occurrence, abides by his own decisions. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], V.xxviii) | |
| A reaction: Notice that the wise man never exhibits weakness of will (an Aristotelian virtue), and is consistent (as Kant proposed), and is patient (as the Stoics proposed). But Cicero doesn't think he should busy himself maximising happiness. |
| 5891 | Philosophy is the collection of rational arguments [Cicero] |
| Full Idea: Philosophy consists in the collection of rational arguments. [Philosophia ex rationum collatione constet] | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], IV.xxxviii.84) | |
| A reaction: A nice epigraph for this database. Philosophy is, I trust, a little more than that, because you don't just hide them away in a drawer. But if you arrange them nicely in a museum (a website, for example), not a lot more can be done. |
| 13733 | Frege considered definite descriptions to be genuine singular terms [Frege, by Fitting/Mendelsohn] |
| Full Idea: Frege (1893) considered a definite description to be a genuine singular term (as we do), so that a sentence like 'The present King of France is bald' would have the same logical form as 'Harry Truman is bald'. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by M Fitting/R Mendelsohn - First-Order Modal Logic | |
| A reaction: The difficulty is what the term refers to, and they embrace a degree of Meinongianism - that is that non-existent objects can still have properties attributed to them, and so can be allowed some sort of 'existence'. |
| 9874 | Contradiction arises from Frege's substitutional account of second-order quantification [Dummett on Frege] |
| Full Idea: The contradiction in Frege's system is due to the presence of second-order quantification, ..and Frege's explanation of the second-order quantifier, unlike that which he provides for the first-order one, appears to be substitutional rather than objectual. | |
| From: comment on Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], §25) by Michael Dummett - Frege philosophy of mathematics Ch.17 | |
| A reaction: In Idea 9871 Dummett adds the further point that Frege lacks a clear notion of the domain of quantification. At this stage I don't fully understand this idea, but it is clearly of significance, so I will return to it. |
| 18252 | Real numbers are ratios of quantities, such as lengths or masses [Frege] |
| Full Idea: If 'number' is the referent of a numerical symbol, a real number is the same as a ratio of quantities. ...A length can have to another length the same ratio as a mass to another mass. | |
| From: Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], III.1.73), quoted by Michael Dummett - Frege philosophy of mathematics 21 'Frege's' | |
| A reaction: This is part of a critique of Cantor and the Cauchy series approach. Interesting that Frege, who is in the platonist camp, is keen to connect the real numbers with natural phenomena. He is always keen to keep touch with the application of mathematics. |
| 18271 | We can't prove everything, but we can spell out the unproved, so that foundations are clear [Frege] |
| Full Idea: It cannot be demanded that everything be proved, because that is impossible; but we can require that all propositions used without proof be expressly declared as such, so that we can see distinctly what the whole structure rests upon. | |
| From: Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], p.2), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 7 'What' |
| 10623 | Frege defined number in terms of extensions of concepts, but needed Basic Law V to explain extensions [Frege, by Hale/Wright] |
| Full Idea: Frege opts for his famous definition of numbers in terms of extensions of the concept 'equal to the concept F', but he then (in 'Grundgesetze') needs a theory of extensions or classes, which he provided by means of Basic Law V. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by B Hale / C Wright - Intro to 'The Reason's Proper Study' §1 |
| 9975 | Frege ignored Cantor's warning that a cardinal set is not just a concept-extension [Tait on Frege] |
| Full Idea: Cantor pointed out explicitly to Frege that it is a mistake to take the notion of a set (i.e. of that which has a cardinal number) to simply mean the extension of a concept. ...Frege's later assumption of this was an act of recklessness. | |
| From: comment on Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by William W. Tait - Frege versus Cantor and Dedekind III | |
| A reaction: ['recklessness' is on p.61] Tait has no sympathy with the image of Frege as an intellectual martyr. Frege had insufficient respect for a great genius. Cantor, crucially, understood infinity much better than Frege. |
| 18165 | My Basic Law V is a law of pure logic [Frege] |
| Full Idea: I hold that my Basic Law V is a law of pure logic. | |
| From: Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893], p.4), quoted by Penelope Maddy - Naturalism in Mathematics I.1 | |
| A reaction: This is, of course, the notorious law which fell foul of Russell's Paradox. It is said to be pure logic, even though it refers to things that are F and things that are G. |
| 18284 | Particulars can be verified or falsified, but general statements can only be falsified (conclusively) [Popper] |
| Full Idea: Whereas particular reality statements are in principle completely verifiable or falsifiable, things are different for general reality statements: they can indeed be conclusively falsified, they can acquire a negative truth value, but not a positive one. | |
| From: Karl Popper (Two Problems of Epistemology [1932], p.256), quoted by J. Alberto Coffa - The Semantic Tradition from Kant to Carnap 18 'Laws' | |
| A reaction: This sounds like a logician's approach to science, but I prefer to look at coherence, where very little is actually conclusive, and one tinkers with the theory instead. |
| 5879 | The soul is the heart, or blood in the heart, or part of the brain, of something living in heart or brain, or breath [Cicero] |
| Full Idea: Some think the soul is the heart; Empedocles holds that the soul is blood in the heart; others said one part of the brain claimed the primacy of soul; others say the heart or brain are habitations of the soul; while others identify soul and breath. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.ix.17-19) | |
| A reaction: A nice survey of views. Note that many of them identify the psuché/anima with physical parts of the body; only the fourth option seems to be dualist. This is despite the contemptuous response to Democritus' atomist theory of soul. |
| 5884 | How can one mind perceive so many dissimilar sensations? [Cicero] |
| Full Idea: Why is it that, using the same mind, we have perception of things so utterly unlike as colour, taste, heat, smell and sound? | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xx.47) | |
| A reaction: This leaves us with the 'binding problem', of how the dissimilar sensations are pulled together into one field of experience. It is a nice simple objection, though, to anyone who simplistically claims that the mind is self-evidently unified. |
| 5887 | The soul has a single nature, so it cannot be divided, and hence it cannot perish [Cicero] |
| Full Idea: In souls there is no mingling of ingredients, nothing of two-fold nature, so it is impossible for the soul to be divided; impossible, therefore, for it to perish either; for perishing is like the separation of parts which were maintained in union. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xxix.71) | |
| A reaction: Cicero knows he is pushing his luck in asserting that perishing is a sort of division. Why can't something be there one moment and gone the next? He appears to be in close agreement with Descartes about being a 'thinking thing'. |
| 5886 | Like the eye, the soul has no power to see itself, but sees other things [Cicero] |
| Full Idea: The soul has not the power of itself to see itself, but, like the eye, the soul, though it does not see itself, yet discerns other things. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xxvii) | |
| A reaction: The soul is a complex item which contributes many layers of interpretation to what it sees, so there is scope for parts of the soul seeing other parts. Somewhere in the middle Cicero seems to be right - there is an elusive something we can't get at. |
| 5885 | Souls contain no properties of elements, and elements contain no properties of souls [Cicero] |
| Full Idea: No beginnings of souls can be found on earth; there is no combination in souls that could be born from earth, nothing that partakes of moist or airy or fiery; for in those elements there is nothing to possess the power of memory, thought, or reflection. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], I.xxvi.66) | |
| A reaction: Interesting, but I think magnetism is an instructive analogy, which has weird properties which we never perceive in elements (though it is there, buried deep - suggesting panpsychism). Cicero would be disconcerted to find that fire isn't an element. |
| 9190 | A concept is a function mapping objects onto truth-values, if they fall under the concept [Frege, by Dummett] |
| Full Idea: In later Frege, a concept could be taken as a particular case of a function, mapping every object on to one of the truth-values (T or F), according as to whether, as we should ordinarily say, that object fell under the concept or not. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by Michael Dummett - The Philosophy of Mathematics 3.5 | |
| A reaction: As so often in these attempts at explanation, this sounds circular. You can't decide whether an object truly falls under a concept, if you haven't already got the concept. His troubles all arise (I say) because he scorns abstractionist accounts. |
| 13665 | Frege took the study of concepts to be part of logic [Frege, by Shapiro] |
| Full Idea: Frege took the study of concepts and their extensions to be within logic. | |
| From: report of Gottlob Frege (Grundgesetze der Arithmetik 1 (Basic Laws) [1893]) by Stewart Shapiro - Foundations without Foundationalism 7.1 | |
| A reaction: This is part of the plan to make logic a universal language (see Idea 13664). I disagree with this, and with the general logicist view of the position of logic. The logical approach thins concepts out. See Deleuze/Guattari's horror at this. |
| 5890 | We should not share the distress of others, but simply try to relieve it [Cicero] |
| Full Idea: We ought not to share distresses ourselves for the sake of others, but we ought to relieve others of their distress if we can. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], IV.xxvi.56) | |
| A reaction: This strikes me as a sensible and balanced attitude. Some people, particularly in a Christian culture, urge that feeling strong and painful compassion for others is an intrinsic good, but the commonsense view is that that just increases human suffering. |
| 5894 | All men except philosophers fear poverty [Cicero] |
| Full Idea: All men are afraid of poverty, but not a single philosopher is so. | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], V.xxxi.88) | |
| A reaction: Not a thought which is encountered very often in modern philosophy journals. If a person is to be 'philosophical' in the way they live, calm endurance of the vicissitudes and hardships of life has to be a key prerequisite. |
| 5895 | If one despises illiterate mechanics individually, they are not worth more collectively [Cicero] |
| Full Idea: Can anything be more foolish than to suppose that those, whom individually one despises as illiterate mechanics, are worth anything collectively? | |
| From: M. Tullius Cicero (Tusculan Disputations [c.44 BCE], V.xxxvi.104) | |
| A reaction: Aristotle disagrees (Idea 2823). In 1906 a huge number of people guessed the weight of a cow at a fair, and the average was within one pound of the truth. In our world the healthy workings of the group are warped by the mass media. |