20 ideas
| 5300 | Philosophers have interpreted the world, but the point is to change it [Marx] |
| Full Idea: The philosophers have only interpreted the world, in various ways; the point is to change it. | |
| From: Karl Marx (Theses on Feuerbach [1846], §XI) | |
| A reaction: The 'point' of what? Personally I am more with Aristotle - that the aim is to create a society in which we can all aspire to contemplate like gods. As an interim statement of aim, though, one must respect Marx. But was he a philosopher? |
| 22820 | Early Romantics sought a plurality of systems, in a quest for freedom [Hösle] |
| Full Idea: It was an early Romantic idea that there is necessarily a plurality of systems in which individuality is expressed; for a complete system would destroy freedom. | |
| From: Vittorio Hösle (A Short History of German Philosophy [2013], 7) | |
| A reaction: I'm not clear why you are free because you are locked into system that differs from that of other people. True freedom seems to be either no system, or continually remaking one's own system. Why is such freedom valuable? Freedom v truth? |
| 5297 | Whether human thinking can be 'true' must be decided in practice, not theory [Marx] |
| Full Idea: The question whether objective truth can be attributed to human thinking is not a question of theory but is a practical question; man must prove the truth of his thinking in practice. | |
| From: Karl Marx (Theses on Feuerbach [1846], §II) | |
| A reaction: This would appear to be an assertion of the pragmatic view of truth well before Peirce. The obvious objections arise, such as whether falsehood (Plato's 'noble lie') might not have equal practical success, and whether truth might be disastrous. |
| 18806 | Frege thought traditional categories had psychological and linguistic impurities [Frege, by Rumfitt] |
| Full Idea: Frege rejected the traditional categories as importing psychological and linguistic impurities into logic. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by Ian Rumfitt - The Boundary Stones of Thought 1.2 | |
| A reaction: Resisting such impurities is the main motivation for making logic entirely symbolic, but it doesn't follow that the traditional categories have to be dropped. |
| 8490 | First-level functions have objects as arguments; second-level functions take functions as arguments [Frege] |
| Full Idea: Just as functions are fundamentally different from objects, so also functions whose arguments are and must be functions are fundamentally different from functions whose arguments are objects. The latter are first-level, the former second-level, functions. | |
| From: Gottlob Frege (Function and Concept [1891], p.38) | |
| A reaction: In 1884 he called it 'second-order'. This is the standard distinction between first- and second-order logic. The first quantifies over objects, the second over intensional entities such as properties and propositions. |
| 8492 | Relations are functions with two arguments [Frege] |
| Full Idea: Functions of one argument are concepts; functions of two arguments are relations. | |
| From: Gottlob Frege (Function and Concept [1891], p.39) | |
| A reaction: Nowadays we would say 'two or more'. Another interesting move in the aim of analytic philosophy to reduce the puzzling features of the world to mathematical logic. There is, of course, rather more to some relations than being two-argument functions. |
| 8487 | Arithmetic is a development of logic, so arithmetical symbolism must expand into logical symbolism [Frege] |
| Full Idea: I am of the opinion that arithmetic is a further development of logic, which leads to the requirement that the symbolic language of arithmetic must be expanded into a logical symbolism. | |
| From: Gottlob Frege (Function and Concept [1891], p.30) | |
| A reaction: This may the the one key idea at the heart of modern analytic philosophy (even though logicism may be a total mistake!). Logic and arithmetical foundations become the master of ontology, instead of the servant. The jury is out on the whole enterprise. |
| 18899 | Frege takes the existence of horses to be part of their concept [Frege, by Sommers] |
| Full Idea: Frege regarded the existence of horses as a property of the concept 'horse'. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by Fred Sommers - Intellectual Autobiography 'Realism' |
| 4028 | Frege allows either too few properties (as extensions) or too many (as predicates) [Mellor/Oliver on Frege] |
| Full Idea: Frege's theory of properties (which he calls 'concepts') yields too few properties, by identifying coextensive properties, and also too many, by letting every predicate express a property. | |
| From: comment on Gottlob Frege (Function and Concept [1891]) by DH Mellor / A Oliver - Introduction to 'Properties' §2 | |
| A reaction: Seems right; one extension may have two properties (have heart/kidneys), two predicates might express the same property. 'Cutting nature at the joints' covers properties as well as objects. |
| 8489 | The concept 'object' is too simple for analysis; unlike a function, it is an expression with no empty place [Frege] |
| Full Idea: I regard a regular definition of 'object' as impossible, since it is too simple to admit of logical analysis. Briefly: an object is anything that is not a function, so that an expression for it does not contain any empty place. | |
| From: Gottlob Frege (Function and Concept [1891], p.32) | |
| A reaction: Here is the core of the programme for deriving our ontology from our logic and language, followed through by Russell and Quine. Once we extend objects beyond the physical, it becomes incredibly hard to individuate them. |
| 22598 | The authentic self exists at the level of class, rather than the individual [Marx, by Dunt] |
| Full Idea: Instead of focusing on the individual, Marxism suggested that the authentic self was at the social level in the form of class. | |
| From: report of Karl Marx (Theses on Feuerbach [1846]) by Ian Dunt - How to be a Liberal 6 | |
| A reaction: [not sure of the best source in Marx] This idea is expressed here by a defender of liberal individualism. Dunt persuasively attacks any concept of the self as part of some group, rather than as being an individual. |
| 9947 | Concepts are the ontological counterparts of predicative expressions [Frege, by George/Velleman] |
| Full Idea: Concepts, for Frege, are the ontological counterparts of predicative expressions. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: That sounds awfully like what many philosophers call 'universals'. Frege, as a platonist (at least about numbers), I would take to be in sympathy with that. At least we can say that concepts seem to be properties. |
| 10319 | An assertion about the concept 'horse' must indirectly speak of an object [Frege, by Hale] |
| Full Idea: Frege had a notorious difficulty over the concept 'horse', when he suggests that if we wish to assert something about a concept, we are obliged to proceed indirectly by speaking of an object that represents it. | |
| From: report of Gottlob Frege (Function and Concept [1891], Ch.2.II) by Bob Hale - Abstract Objects | |
| A reaction: This sounds like the thin end of a wedge. The great champion of objects is forced to accept them here as a façon de parler, when elsewhere they have ontological status. |
| 8488 | A concept is a function whose value is always a truth-value [Frege] |
| Full Idea: A concept in logic is closely connected with what we call a function. Indeed, we may say at once: a concept is a function whose value is always a truth-value. ..I give the name 'function' to what is meant by the 'unsaturated' part. | |
| From: Gottlob Frege (Function and Concept [1891], p.30) | |
| A reaction: So a function becomes a concept when the variable takes a value. Problems arise when the value is vague, or the truth-value is indeterminable. |
| 9948 | Unlike objects, concepts are inherently incomplete [Frege, by George/Velleman] |
| Full Idea: For Frege, concepts differ from objects in being inherently incomplete in nature. | |
| From: report of Gottlob Frege (Function and Concept [1891]) by A.George / D.J.Velleman - Philosophies of Mathematics Ch.2 | |
| A reaction: This is because they are 'unsaturated', needing a quantified variable to complete the sentence. This could be a pointer towards Quine's view of properties, as simply an intrinsic feature of predication about objects, with no separate identity. |
| 4972 | I may regard a thought about Phosphorus as true, and the same thought about Hesperus as false [Frege] |
| Full Idea: From sameness of meaning there does not follow sameness of thought expressed. A fact about the Morning Star may express something different from a fact about the Evening Star, as someone may regard one as true and the other false. | |
| From: Gottlob Frege (Function and Concept [1891], p.14) | |
| A reaction: This all gets clearer if we distinguish internalist and externalist theories of content. Why take sides on this? Why not just ask 'what is in the speaker's head?', 'what does the sentence mean in the community?', and 'what is the corresponding situation?' |
| 5298 | The human essence is not found in individuals but in social relations [Marx] |
| Full Idea: The human essence is no abstraction inherent in each single individual; in its reality it is the ensemble of the social relations. | |
| From: Karl Marx (Theses on Feuerbach [1846], §VI) | |
| A reaction: This is a key Marxist doctrine, and the central difference from Aristotle. Personally I am more with Aristotle, but the truth obviously lies somewhere in between. Man must be a 'social being', or there wouldn't be any social relations. |
| 22819 | In the 18th century history came to be seen as progressive, rather than cyclical [Hösle] |
| Full Idea: The turning point in the history of the philosophy of history occurs in the eighteenth century, when the ancient cyclical model of Vico is superseded by the idea of progress. | |
| From: Vittorio Hösle (A Short History of German Philosophy [2013], 6) | |
| A reaction: He says that Hegel merely inherited this progressive view, rather than creating it. I'm not sure how widely held the cyclical view was. I don't recognise it in Shakespeare. Science and technology must have suggested progress. |
| 8491 | The Ontological Argument fallaciously treats existence as a first-level concept [Frege] |
| Full Idea: The ontological proof of God's existence suffers from the fallacy of treating existence as a first-level concept. | |
| From: Gottlob Frege (Function and Concept [1891], p.38 n) | |
| A reaction: [See Idea 8490 for first- and second-order functions] This is usually summarised as the idea that existence is a quantifier rather than a predicate. |
| 5299 | Religious feeling is social in origin [Marx] |
| Full Idea: The "religious sentiment" (discussed by Feuerbach) is itself a social product. | |
| From: Karl Marx (Theses on Feuerbach [1846], §VII) | |
| A reaction: Recent brain research has identified a part of the brain which is only active during religious thought and experience. It is easy to produce cynical political accounts of religion, but in its time it was also quite a good scientific account of nature. |