5 ideas
| 23367 | Even pointing a finger should only be done for a reason [Epictetus] |
| Full Idea: Philosophy says it is not right even to stretch out a finger without some reason. | |
| From: Epictetus (fragments/reports [c.57], 15) | |
| A reaction: The key point here is that philosophy concerns action, an idea on which Epictetus is very keen. He rather despise theory. This idea perfectly sums up the concept of the wholly rational life (which no rational person would actually want to live!). |
| 13827 | Logical consequence isn't a black box (Tarski's approach); we should explain how arguments work [Prawitz] |
| Full Idea: Defining logical consequence in the way Tarski does is a rather meagre result, treating an argument as a black box, observing input and output, while disregarding inner structure. We should define logical consequence on the basis of valid arguments. | |
| From: Dag Prawitz (On the General Idea of Proof Theory [1974], §2) |
| 13826 | Model theory looks at valid sentences and consequence, but not how we know these things [Prawitz] |
| Full Idea: In model theory, which has dominated the last decades, one concentrates on logically valid sentences, and what follows logically from what, but one disregards questions concerning how we know these things. | |
| From: Dag Prawitz (On the General Idea of Proof Theory [1974], §1) |
| 13197 | The notion of substance is one of the keys to true philosophy [Leibniz] |
| Full Idea: I consider the notion of substance to be one of the keys to the true philosophy. ....I imagine that philosophers will one day know the notion of substance a bit better than they do now. | |
| From: Gottfried Leibniz (Letters to Thomas Burnett [1703], 1699.01.20/30) | |
| A reaction: This is a controversial remark at this historical moment, when the apparent Aristotelian commitment to substances was becoming discredited. Personally I would eliminate substance, but not just because physicists don't refer to it. |
| 13198 | Gravity is within matter because of its structure, and it can be explained. [Leibniz] |
| Full Idea: I believe that both gravity and elasticity are in matter only because of the structure of the system and can be explained mechanically or through impulsion. | |
| From: Gottfried Leibniz (Letters to Thomas Burnett [1703], 1699 draft) | |
| A reaction: The significance of this remark is that gravity is held (in full knowledge of Newton's work) to be within matter, and not imposed from the outside. I believe we now postulate a particle as part of the explanation. |