48 ideas
| 1502 | Parmenides was much more cautious about accepting ideas than his predecessors [Simplicius on Parmenides] |
| 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] |
| 8250 | So-called 'free logic' operates without existence assumptions [Meinong, by George/Van Evra] |
| 449 | Being is not divisible, since it is all alike [Parmenides] |
| 448 | No necessity could produce Being either later or earlier, so it must exist absolutely or not at all [Parmenides] |
| 447 | Being must be eternal and uncreated, and hence it is timeless [Parmenides] |
| 445 | The realm of necessary non-existence cannot be explored, because it is unknowable [Parmenides] |
| 1503 | There is no such thing as nothing [Parmenides] |
| 21820 | Parmenides at least saw Being as the same as Nous, and separate from the sensed realm [Parmenides, by Plotinus] |
| 452 | All our concepts of change and permanence are just names, not the truth [Parmenides] |
| 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] |
| 8719 | There can be impossible and contradictory objects, if they can have properties [Meinong, by Friend] |
| 8971 | There are objects of which it is true that there are no such objects [Meinong] |
| 8718 | Meinong says an object need not exist, but must only have properties [Meinong, by Friend] |
| 7756 | Meinong said all objects of thought (even self-contradictions) have some sort of being [Meinong, by Lycan] |
| 15781 | The objects of knowledge are far more numerous than objects which exist [Meinong] |
| 1504 | Something must be unchanging to make recognition and knowledge possible [Aristotle on Parmenides] |
| 444 | The first way of enquiry involves necessary existence [Parmenides] |
| 450 | Necessity sets limits on being, in order to give it identity [Parmenides] |
| 451 | Thinking implies existence, because thinking depends on it [Parmenides] |
| 1506 | Parmenides treats perception and intellectual activity as the same [Theophrastus on Parmenides] |
| 3058 | Only reason can prove the truth of facts [Parmenides] |
| 555 | People who say that the cosmos is one forget that they must explain movement [Aristotle on Parmenides] |
| 226 | The one is without any kind of motion [Parmenides] |
| 5081 | There could be movement within one thing, as there is within water [Aristotle on Parmenides] |
| 1509 | The one can't be divisible, because if it was it could be infinitely divided down to nothing [Parmenides, by Simplicius] |
| 20900 | Defenders of the One say motion needs the void - but that is not part of Being [Parmenides, by Aristotle] |
| 1505 | Reason sees reality as one, the senses see it as many [Aristotle on Parmenides] |
| 453 | Reality is symmetrical and balanced, like a sphere, with no reason to be greater one way rather than another [Parmenides] |
| 1792 | He taught that there are two elements, fire the maker, and earth the matter [Parmenides, by Diog. Laertius] |
| 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] |
| 5115 | It is feeble-minded to look for explanations of everything being at rest [Aristotle on Parmenides] |
| 20965 | Leibniz upheld conservations of momentum and energy [Leibniz, by Papineau] |
| 13217 | The void can't exist, and without the void there can't be movement or separation [Parmenides, by Aristotle] |
| 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] |
| 22918 | What could have triggered the beginning [of time and being]? [Parmenides] |
| 1794 | He was the first to discover the identity of the Morning and Evening Stars [Parmenides, by Diog. Laertius] |
| 1791 | He was the first person to say the earth is spherical [Parmenides, by Diog. Laertius] |
| 22894 | If time were absolute that would make God's existence dependent on it [Leibniz, by Bardon] |
| 2099 | The existence of God, and all metaphysics, follows from the Principle of Sufficient Reason [Leibniz] |