24 ideas
| 8868 | Objective truth arises from interpersonal communication [Davidson] |
| Full Idea: The source of the concept of objective truth is interpersonal communication. | |
| From: Donald Davidson (Three Varieties of Knowledge [1991], p.209) | |
| A reaction: This is a distinctively Davidsonian idea, arising out of Wittgenstein's Private Language Argument. We could go a step further, and just say that 'objectivity is a social concept'. Davidson more or less pleads guilty to pragmatism in this essay. |
| 21110 | An understanding of the most basic physics should explain all of the subject's mysteries [Krauss] |
| Full Idea: Once we understood the fundamental laws that govern forces of nature at its smallest scales, all of these current mysteries would be revealed as natural consequences of these laws. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 08) | |
| A reaction: This expresses the reductionist view within physics itself. Krauss says the discovery that empty space itself contains energy has led to a revision of this view (because that is not part of the forces and particles studied in basic physics). |
| 21105 | In 1676 it was discovered that water is teeming with life [Krauss] |
| Full Idea: Van Leeuwenhoek first stared at a drop of seemingly empty water with a microscope in 1676 and discovered in was teeming with life. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: I am convinced that this had a huge influence on Leibniz's concept of monads. He immediately became convinced that it was some sort of life all the way down. He would be have been disappointed by the subsequent chemical reduction of life. |
| 15127 | A categorical basis could hardly explain a disposition if it had no powers of its own [Hawthorne] |
| Full Idea: The categorical basis would be a poor explanans for the disposition as explanandum, if the categorical basis did not drag any causal powers along with it. | |
| From: John Hawthorne (Causal Structuralism [2001], 2.4) | |
| A reaction: The idea that the world is explained just by some basic stuff having qualities and relations always strikes me as wrong, because the view of nature is too passive. |
| 15123 | Is the causal profile of a property its essence? [Hawthorne] |
| Full Idea: We might say that the causal profile of a property is its essence. | |
| From: John Hawthorne (Causal Structuralism [2001], Intro) | |
| A reaction: I associate this view with Shoemaker, and find it sympathetic. We always want to know more. What gives rise to these causal powers? Where does explanation end? He notes that you might say some of the powers are non-essential. |
| 15122 | Could two different properties have the same causal profile? [Hawthorne] |
| Full Idea: If there is more to the nature of a property than the causal powers that it confers, then two different internal natures of properties might necessitate the same causal profile. | |
| From: John Hawthorne (Causal Structuralism [2001], Intro) | |
| A reaction: If the causal profiles were identical, it is hard to see how we could even propose, let alone test, their intrinsic difference. ...Unless, perhaps, we knew that the properties arose from different substrata. |
| 15124 | If properties are more than their powers, we could have two properties with the same power [Hawthorne] |
| Full Idea: If a property is something over and above its causal profile, we seem to have conceptual space for an electron to have negative charge 1 and negative charge 2, that have exactly the same causal powers. | |
| From: John Hawthorne (Causal Structuralism [2001], 1.3) |
| 15128 | We can treat the structure/form of the world differently from the nodes/matter of the world [Hawthorne] |
| Full Idea: It does not seem altogether arbitrary to treat the structure of the world (the 'form' of the world) in a different way to the nodes in the structure (the 'matter' of the world). | |
| From: John Hawthorne (Causal Structuralism [2001], 2.5) | |
| A reaction: An interesting contemporary spin put on Aristotle's original view. Hawthorne is presenting the Aristotle account as a sort of 'structuralism' about nature. |
| 15121 | An individual essence is a necessary and sufficient profile for a thing [Hawthorne] |
| Full Idea: An individual essence is a profile that is necessary and sufficient for some particular thing. | |
| From: John Hawthorne (Causal Structuralism [2001], Intro) | |
| A reaction: By 'for' he presumably means for the thing to have an existence and a distinct identity. If it retained its identity, but didn't function any more, would that be loss of essence? |
| 8867 | A belief requires understanding the distinctions of true-and-false, and appearance-and-reality [Davidson] |
| Full Idea: Having a belief demands in addition appreciating the contrast between true belief and false, between appearance and reality, mere seeming and being. | |
| From: Donald Davidson (Three Varieties of Knowledge [1991], p.209) | |
| A reaction: This sets the bar very high for belief (never mind knowledge), and seems to imply that animals don't have beliefs. How should we describe their cognitive states then? I would say these criteria only apply to actual knowledge. |
| 10347 | Objectivity is intersubjectivity [Davidson] |
| Full Idea: An entity is objective in so far as it is intersubjective. | |
| From: Donald Davidson (Three Varieties of Knowledge [1991]), quoted by Martin Kusch - Knowledge by Agreement Ch.10 | |
| A reaction: This thought baffled me until I saw it in the context of socialised epistemology. Effectively objectivity is subsumed under justification, which in turn is seen in a social context, not private to individuals. |
| 8866 | If we know other minds through behaviour, but not our own, we should assume they aren't like me [Davidson] |
| Full Idea: If the mental states of others are known only through their behavioral and other outward manifestations, while this is not true of our own mental states, why should we think our own mental states are anything like those of others? | |
| From: Donald Davidson (Three Varieties of Knowledge [1991], p.207) | |
| A reaction: His point is that if you seriously doubt other minds, you should follow through on the implications. But that is to treat it as a theory about other minds, rather an a sceptical worry. Descartes didn't walk into walls while writing Meditation 1. |
| 10346 | Knowing other minds rests on knowing both one's own mind and the external world [Davidson, by Dummett] |
| Full Idea: Davidson argues that knowledge of other minds presupposes knowledge of one's own mind, and that there is no knowledge of other minds without knowledge of the external world. | |
| From: report of Donald Davidson (Three Varieties of Knowledge [1991]) by Michael Dummett - Common Sense and Physics Ch.10 | |
| A reaction: Davidson't argument is actually hard to swallow because it is so long and complex. Compressing the point makes it begin to sound like a variant of the argument from analogy. |
| 8870 | Content of thought is established through communication, so knowledge needs other minds [Davidson] |
| Full Idea: Until a baseline has been established by communication with someone else, there is no point is saying one's own thoughts have a propositional content. Hence knowledge of another mind is essential all thought and all knowledge. | |
| From: Donald Davidson (Three Varieties of Knowledge [1991], p.213) | |
| A reaction: This really is building a skyscraper on the slightly shaky claims of the Private Language Argument (e.g. Idea 4158). Animals are so important in discussions of this kind. Is an albatross more or less devoid of thought and belief? |
| 8869 | The principle of charity attributes largely consistent logic and largely true beliefs to speakers [Davidson] |
| Full Idea: Concerning charity, the Principle of Coherence seeks logical consistency in the thought of the speaker, and the Principle of Correspondence seeks a similar response to features of the world to that of an interpreter. The speaker has logic and true belief. | |
| From: Donald Davidson (Three Varieties of Knowledge [1991], p.211) | |
| A reaction: Davidson adds a Kantian commitment to pure and universal reason to the very sceptical framework created by Quine. I agree with Davidson, but it seems more like faith than like an argument or an empirical observation. |
| 15126 | Maybe scientific causation is just generalisation about the patterns [Hawthorne] |
| Full Idea: Perhaps science doesn't need a robust conception of causation, and can get by with thinking of causal laws in a Humean way, as the simplest generalization over the mosaic. | |
| From: John Hawthorne (Causal Structuralism [2001], 1.5) | |
| A reaction: The Humean view he is referring to is held by David Lewis. That seems a council of defeat. We observe from a distance, but make no attempt to explain. |
| 15125 | We only know the mathematical laws, but not much else [Hawthorne] |
| Full Idea: We know the laws of the physical world, in so far as they are mathematical, pretty well, but we know nothing else about it. | |
| From: John Hawthorne (Causal Structuralism [2001], Ch.25) | |
| A reaction: Lovely remark [spotted by Hawthorne]. This sums up exactly what I take to be the most pressing issue in philosophy of science - that we develop a view of science that has space for the next step in explanation. |
| 21109 | Space itself can expand (and separate its contents) at faster than light speeds [Krauss] |
| Full Idea: Special Relativity says nothing can travel 'through space' faster than the speed of light. But space itself can do whatever the heck it wants, at least in general relativity. And it can carry distant objects apart from one another at superluminal speeds | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 06) | |
| A reaction: Another of my misunderstandings corrected. I assumed that the event horizon (limit of observability) was defined by the stuff retreating at (max) light speed. But beyond that it retreats even faster! What about the photons in space? |
| 21104 | General Relativity: the density of energy and matter determines curvature and gravity [Krauss] |
| Full Idea: The left-hand side of the general relativity equations descrbe the curvature of the universe, and the strength of gravitational forces acting on matter and radiation. The right-hand sides reflect the total density of all kinds of energy and matter. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: I had assumed that the equations just described the geometry. In fact the matter determines the nature of the universe in which it exists. Presumably only things with mass get a vote. |
| 21107 | Uncertainty says that energy can be very high over very short time periods [Krauss] |
| Full Idea: The Heisenberg Uncertainty Principle says that the uncertainty in the measured energy of a system is inversely proportional to the length of time over which you observe it. (This allow near infinite energy over very short times). | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: Apparently this brief energy is 'borrowed', and must be quickly repaid. |
| 21106 | Most of the mass of a proton is the energy in virtual particles (rather than the quarks) [Krauss] |
| Full Idea: The quarks provide very little of the total mass of a proton, and the fields created by the virtual particles contribute most of the energy that goes into the proton's rest energy and, hence, its mass. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 04) | |
| A reaction: He gives an artist's impression of the interior of a proton, which looks like a ship's engine room. |
| 21112 | Empty space contains a continual flux of brief virtual particles [Krauss] |
| Full Idea: Empty space is complicated. It is a boiling brew of virtual particles that pop in and out of existence in a time so short we cannot see them directly. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 10) | |
| A reaction: Apparently the interior of a proton is also like this. This fact gives a foot in the door for explanations of how the Big Bang got started, from these virtual particles. And yet surely space itself only arrives with the Big Bang? |
| 21108 | The universe is precisely 13.72 billion years old [Krauss] |
| Full Idea: We now know the age of the universe to four significant figures. It is 13.72 billion years old! | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 05) | |
| A reaction: It amazes me how many people, especially in philosophy, would be reluctant to accept that this is a know fact. I'm not accepting its certainty, but an assertion like this from a leading figure is good enough for me, and it should be for you. |
| 21111 | It seems likely that cosmic inflation is eternal, and this would make a multiverse inevitable [Krauss] |
| Full Idea: A multiverse is inevitable if inflation is eternal, and eternal inflation is by far the most likely possibility in most, if not all, inflationary scenarios. | |
| From: Lawrence M. Krauss (A Universe from Nothing [2012], 08) |