29 ideas
2098 | The principle of sufficient reason is needed if we are to proceed from maths to physics [Leibniz] |
3646 | There is always a reason why things are thus rather than otherwise [Leibniz] |
2104 | No reason could limit the quantity of matter, so there is no limit [Leibniz] |
18806 | Frege thought traditional categories had psychological and linguistic impurities [Frege, by Rumfitt] |
17751 | Gödel proved the completeness of first order predicate logic in 1930 [Gödel, by Walicki] |
8490 | First-level functions have objects as arguments; second-level functions take functions as arguments [Frege] |
8492 | Relations are functions with two arguments [Frege] |
8487 | Arithmetic is a development of logic, so arithmetical symbolism must expand into logical symbolism [Frege] |
18899 | Frege takes the existence of horses to be part of their concept [Frege, by Sommers] |
19385 | All simply substances are in harmony, because they all represent the one universe [Leibniz] |
21346 | The ratio between two lines can't be a feature of one, and cannot be in both [Leibniz] |
4028 | Frege allows either too few properties (as extensions) or too many (as predicates) [Mellor/Oliver on Frege] |
8489 | The concept 'object' is too simple for analysis; unlike a function, it is an expression with no empty place [Frege] |
9947 | Concepts are the ontological counterparts of predicative expressions [Frege, by George/Velleman] |
10319 | An assertion about the concept 'horse' must indirectly speak of an object [Frege, by Hale] |
8488 | A concept is a function whose value is always a truth-value [Frege] |
9948 | Unlike objects, concepts are inherently incomplete [Frege, by George/Velleman] |
4972 | I may regard a thought about Phosphorus as true, and the same thought about Hesperus as false [Frege] |
2106 | The only simple things are monads, with no parts or extension [Leibniz] |
2102 | Atomism is irrational because it suggests that two atoms can be indistinguishable [Leibniz] |
2105 | Things are infinitely subdivisible and contain new worlds, which atoms would make impossible [Leibniz] |
20965 | Leibniz upheld conservations of momentum and energy [Leibniz, by Papineau] |
2103 | The idea that the universe could be moved forward with no other change is just a fantasy [Leibniz] |
2100 | Space and time are purely relative [Leibniz] |
2107 | No time exists except instants, and instants are not even a part of time, so time does not exist [Leibniz] |
2101 | If everything in the universe happened a year earlier, there would be no discernible difference [Leibniz] |
22894 | If time were absolute that would make God's existence dependent on it [Leibniz, by Bardon] |
8491 | The Ontological Argument fallaciously treats existence as a first-level concept [Frege] |
2099 | The existence of God, and all metaphysics, follows from the Principle of Sufficient Reason [Leibniz] |