39 ideas
| 6961 | An analogy begins to break down as soon as the two cases differ [Hume] |
| Full Idea: But wherever you depart, in the least, from the similarity of the cases, you diminish proportionably the evidence; and may at last bring it to a very weak analogy. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 2) |
| 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. |
| 21285 | Events are baffling before experience, and obvious after experience [Hume] |
| Full Idea: Every event, before experience, is equally difficult and incomprehensible; and every event, after experience, is equally easy and intelligible. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 8) | |
| A reaction: If you don't believe this, spend some time watching documentaries about life in the deep oceans. Things beyond imagination swim around in front of you. But we can extrapolate, once the possibilities are revealed by experience. |
| 22109 | The fullest knowledge places a conclusion within an accurate theory [Aquinas, by Kretzmann/Stump] |
| Full Idea: Having 'scientia' is the fullest possible human cognition, by which one situates the fact expressed by a conclusion in an explanatory theory that accurately maps metaphysical or physical reality. | |
| From: report of Thomas Aquinas (Sententia on 'Posterior Analytics' [1269], 1.2.9, 1.5.7) by Kretzmann/Stump - Aquinas, Thomas 11 | |
| A reaction: That is a perfect statement of my concept of knowledge. Explanatory theories must specify the essential natures of the entities involved. We don't aim for 'knowledge', we aim for the 'fullest possible cognition'. This account extend's Aristotle's. |
| 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?' |
| 6959 | We can't assume God's perfections are like our ideas or like human attributes [Hume] |
| Full Idea: But let us beware, lest we think, that our ideas anywise correspond to his perfections, or that his attributes have any resemblance to these qualities among men. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 2) |
| 6957 | The objects of theological reasoning are too big for our minds [Hume] |
| Full Idea: But in theological reasonings … we are employed upon objects, which, we must be sensible, are too large for our grasp. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 1) |
| 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. |
| 21255 | No being's non-existence can imply a contradiction, so its existence cannot be proved a priori [Hume] |
| Full Idea: Nothing that is distinctly conceivable implies a contradiction. Whatever we conceive of as existent we can also conceive as non-existent. So there is no being whose non-existence implies a contradiction. So no being's existence is demonstrable. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 9) | |
| A reaction: I totally subscribe to this idea, and take claims that nature actually contains contradictions (based on the inevitable quantum mechanics) to be ridiculous. Nature is the embodiment, chief exemplar and prime test of consistency. |
| 21254 | A chain of events requires a cause for the whole as well as the parts, yet the chain is just a sum of parts [Hume] |
| Full Idea: The whole chain or succession [of causes and effects], taken together, is not caused by anything, and yet it is evident that it requires a cause or reason, as much as any particular object which begins to exist in time. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 9) | |
| A reaction: This is such a major and significant idea. With blinkers on we think our questions are answered. Then someone (a philosopher, inevitably) makes you pull back and ask a much wider and more difficult question. |
| 1435 | If something must be necessary so that something exists rather than nothing, why can't the universe be necessary? [Hume] |
| Full Idea: What was it that determined something to exist rather than nothing? ...This implies a necessary being… But why may not the material universe be the necessarily existent being? | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 9) | |
| A reaction: There certainly seems no need for whatever the necessary thing is that it qualify as a 'god'. If could be a necessary subatomic particle that suddenly triggers reactions. |
| 6962 | The thing which contains order must be God, so see God where you see order [Hume] |
| Full Idea: By supposing something to contain the principle of its order within itself, we really assert it to be God; and the sooner we arrive at that divine being, so much the better. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 4) |
| 6958 | How can we pronounce on a whole after a brief look at a very small part? [Hume] |
| Full Idea: A very small part of this great system, during a very short time, is very imperfectly discovered to us: and do we thence pronounce decisively concerning the origin of the whole? | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 2) |
| 6963 | Why would we infer an infinite creator from a finite creation? [Hume] |
| Full Idea: By this method of reasoning, you renounce all claim to infinity in any of the attributes of the deity. For … the cause ought only to be proportioned to the effect, and the effect, so far as it falls under our cognizance, is not infinite. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) |
| 6960 | Analogy suggests that God has a very great human mind [Hume] |
| Full Idea: Since the effects resemble, we must infer by analogy that the causes also resemble; and that the Author of Nature is somewhat similar to the mind of man, though possessed of much larger faculties, proportioned to the grandeur of his work. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 2) |
| 6965 | The universe may be the result of trial-and-error [Hume] |
| Full Idea: Many worlds might have been botched and bungled, throughout an eternity, ere this system was struck out. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) |
| 6967 | Order may come from an irrational source as well as a rational one [Hume] |
| Full Idea: Why an orderly system may not be spun from the belly as well as from the brain, it will be difficult … to give a satisfactory reason. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 7) |
| 21282 | Design cannot prove a unified Deity. Many men make a city, so why not many gods for a world? [Hume] |
| Full Idea: How can you prove the unity of a Deity? A great number of men join in building a house or ship, in rearing a city; why may not several deities combine in contriving and framing a world? | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) | |
| A reaction: You might look at the Cistine Chapel ceiling and conclude that only a team could have achieve such a thing. Since there is no way to infer how many gods might be involved, then one god is a possible theory. |
| 21280 | From a ship you would judge its creator a genius, not a mere humble workman [Hume] |
| Full Idea: It is uncertain whether all the excellences of the work can justly be ascribed to the workman. If we survey a ship, what an exalted idea must we form of the ingenuity of the carpenter ...and what surprise must we feel when we find him a stupid mechanic. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) | |
| A reaction: You can at least infer that the ship was not made entirely by makers who are ignorant of carpentry. Somewhere in the divine team there must exist the skills that produce whatever we observe? |
| 21281 | This excellent world may be the result of a huge sequence of trial-and-error [Hume] |
| Full Idea: Many worlds might have been botched and bungled, throughout an eternity, ere this system was struck out; many fruitless trials made, and a slow but continued improvement carried on during infinite ages in the art of world-making. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) | |
| A reaction: Lee Smolin, a modern cosmographer, suggests that this evolution may have led to the current universe, after a long train of selective creations. The idea of natural selection was waiting to happen in 1760. |
| 21283 | Humans renew their species sexually. If there are many gods, would they not do the same? [Hume] |
| Full Idea: Men are mortal and renew their species by generation. Why must this circumstance, so universal, so essential, be excluded from those numerous and limited deities? | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) | |
| A reaction: Hume observes that this would be like the Greek gods. Hume makes mincemeat of attempts to prove the existence of God merely by analogy with human affairs. |
| 6966 | Creation is more like vegetation than human art, so it won't come from reason [Hume] |
| Full Idea: If the universe is more like animal bodies and vegetables than works of human art, it is more probable that its cause resembles the cause of the former than of the latter, and its cause should be ascribed to generation rather than to reason of design. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 7) |
| 21284 | This Creator god might be an infant or incompetent or senile [Hume] |
| Full Idea: [Maybe] this world ...was only the first essay of some infant deity ...or it is the work only of some dependent, inferior deity, the object of derision to his superiors ...or it is the product of the dotage of some superannuated deity... | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) | |
| A reaction: His opponent in the dialogue rejoices that, in the face of these sacreligious fantasies, Hume still accepts the likelihood of some sort of design. Hume is right that it is not much of a theory if nothing can be said about the Designer. |
| 21286 | Motion often begins in matter, with no sign of a controlling agent [Hume] |
| Full Idea: Motion in many instances begins in matter, without any known voluntary agent; to suppose always, in these cases, an unknown voluntary agent is mere hypothesis, attended with no advantages. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 8) | |
| A reaction: This is the modern 'powers' view of science, and a direct contradiction of Plato's claims in The Laws. It seems a bit primitive to assume that magnetism must be the work of some god. |
| 21287 | The universe could settle into superficial order, without a designer [Hume] |
| Full Idea: The universe goes on in a succession of chaos and disorder. But is it not possible that it may settle at last, so as not to lose its inherent motion and active force, yet so as to produce a uniformity of appearance, amidst the continual fluctuation. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 8) | |
| A reaction: From what I know of the constant fluctuation of virtual particles (e.g. inside protons) this is exactly what actually is happening. There is an 'appearance' of order, but at the lowest level this is not the case. |
| 21288 | Ideas arise from objects, not vice versa; ideas only influence matter if they are linked [Hume] |
| Full Idea: In all known instances, ideas are copied from real objects. You reverse this order and give thought the precedence. ...Thought has no influence upon matter except where that matter is so conjoined with it as to have an equal reciprocal influence upon it. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 8) | |
| A reaction: He allows something like mental causation, provided mind and brain are closely linked. Hume brings out the close relationship between divine design theories, and the mind-body problem. |
| 21256 | A surprise feature of all products of 9 looks like design, but is actually a necessity [Hume] |
| Full Idea: The products of 9 always compose either 9 or some lesser product of 9, if you add the characters of the product. To a superficial observer this regularity appears as chance or design, but a skilful algebraist sees it as necessity. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 9) | |
| A reaction: An example of this universal generality is that 369 is a product of 9 (9x41), and if you add 3, 6 and 9 you get 18, which is 2x9. Similar examples occur in nature, such as crystals, which are necessary once the atomic structure is known. |
| 6964 | From our limited view, we cannot tell if the universe is faulty [Hume] |
| Full Idea: It is impossible for us to tell, from our limited views, whether this system contains any great faults. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) |
| 21279 | If the divine cause is proportional to its effects, the effects are finite, so the Deity cannot be infinite [Hume] |
| Full Idea: By this method of reasoning you renounce all claim to infinity in any of the attributes of the Deity. The cause ought to be proportional to the effect, and the effect, so far as it falls under our cognizance, is not infinite. | |
| From: David Hume (Dialogues Concerning Natural Religion [1751], Part 5) | |
| A reaction: You cannot deny that the Deity MAY be infinite, be only accept that your evidence is not enough to prove it. But if nothing infinite has been observed, it is a reasonable provisional inference that nothing infinite exists. |