9 ideas
| 17962 | The truth-maker principle is that every truth has a sufficient truth-maker [Forrest] |
| Full Idea: Item x is said to be a sufficient truth-maker for truth-bearer p just in case necessarily if x exists then p is true. ...Every truth has a sufficient truth-maker. Hence, I take it, the sum of all sufficient truth-makers is a universal truth-maker. | |
| From: Peter Forrest (General Facts,Phys Necessity, and Metaph of Time [2006], 1) | |
| A reaction: Note that it is not 'necessary', because something else might make p true instead. |
| 23026 | We know mathematical axioms, such as subtracting equals from equals leaves equals, by a natural light [Leibniz] |
| Full Idea: It is by the natural light that the axioms of mathematics are recognised. If we take away the same quantity from two equal things, …a thing we can easily predict without having experienced it. | |
| From: Gottfried Leibniz (Letters to Queen Charlotte [1702], p.189) | |
| A reaction: He also says two equal weights will keep a balance level. Plato thinks his slave boy understands halving an area by the natural light, but that is just as likely to be experience. It is too easy to attribut thoughts to a 'natural light'. |
| 13189 | A necessary feature (such as air for humans) is not therefore part of the essence [Leibniz] |
| Full Idea: That which is necessary for something does not constitute its essence. Air is necessary for our life, but our life is something other than air. | |
| From: Gottfried Leibniz (Letters to Queen Charlotte [1702], 1702) | |
| A reaction: Bravo. Why can't modern philosophers hang on to this distinction? They seem to think that because they don't believe in traditional essences they can purloin the word for something else. Same with the word 'abstraction'. |
| 19432 | Intelligible truth is independent of any external things or experiences [Leibniz] |
| Full Idea: Intelligible truth is independent of the truth or of the existence outside us of sensible and material things. ....It is generally true that we only know necessary truths by the natural light [of reason] | |
| From: Gottfried Leibniz (Letters to Queen Charlotte [1702], 1702) | |
| A reaction: A nice quotation summarising a view for which Leibniz is famous - that there is a tight correlation between necessary truths and our a priori knowledge of them. The obvious challenge comes from Kripke's claim that scientists can discover necessities. |
| 19430 | We know objects by perceptions, but their qualities don't reveal what it is we are perceiving [Leibniz] |
| Full Idea: We use the external senses ...to make us know their particular objects ...but they do not make us know what those sensible qualities are ...whether red is small revolving globules causing light, heat a whirling of dust, or sound is waves in air. | |
| From: Gottfried Leibniz (Letters to Queen Charlotte [1702], 1702) | |
| A reaction: These seems to be exactly the concept of secondary qualities which Locke was promoting. They are unreliable information about the objects we perceive. Primary qualities are reliable information. I like that distinction. |
| 19431 | There is nothing in the understanding but experiences, plus the understanding itself, and the understander [Leibniz] |
| Full Idea: It can be said that there is nothing in the understanding which does not come from the senses, except the understanding itself, or that which understands. | |
| From: Gottfried Leibniz (Letters to Queen Charlotte [1702], 1702) | |
| A reaction: Given that Leibniz is labelled as a 'rationalist', this is awfully close to empiricism. Not Locke's 'tabula rasa' perhaps, but Hume's experiences plus associations. Leibniz has a much loftier notion of understanding and reason than Hume does. |
| 7876 | Even if we identify pain with neural events, we can't explain why those neurons cause that feeling [Levine, by Papineau] |
| Full Idea: Materialists identify pain with the firing of nociceptive-specific neurons in the parietal cortex. Even so, Levine argues, we will still lack any explanation of why nociceptive-specific neurons yield pain. | |
| From: report of Joseph Levine (Purple Haze [2001]) by David Papineau - Thinking about Consciousness 5.1 | |
| A reaction: [Proposed by Levine in 1983] I don't think we need to instantly go dualist when faced with this, but we may all eventually have to concede a bit of mysterianism. The explanation may be holistic (and hence hopelessly complex). |
| 7877 | Only phenomenal states have an explanatory gap; water is fully explained by H2O [Levine, by Papineau] |
| Full Idea: Levine says the explanatory gap is peculiar to phenomenal states. Once water has been identified with H2O, or temperature with mean kinetic energy, we do not continue to ask why H2O yields water, or why mean kinetic energy yields temperature. | |
| From: report of Joseph Levine (Purple Haze [2001]) by David Papineau - Thinking about Consciousness 5.1 | |
| A reaction: Everything is mysterious if you think about if for long enough. What about a representational gap? Why do those neurons represent that tree (if the neurons aren't tree-shaped)? To understand qualia, we must understand the whole brain, I suspect. |
| 7878 | Materialism won't explain phenomenal properties, because the latter aren't seen in causal roles [Papineau on Levine] |
| Full Idea: We cannot give materialist explanations of why brain yields phenomenal properties because phenomenal concepts are not associated with descriptions of causal roles in the same way as pre-theoretical terms in other areas of science. | |
| From: comment on Joseph Levine (Purple Haze [2001]) by David Papineau - Thinking about Consciousness 5.1 | |
| A reaction: I think Papineau has part of the answer, and I certainly like his notion of Conceptual Dualism, but if qualia are physical, there must be a physical account of how they acquire their properties. I think the whole brain needs to be understood first. |