7 ideas
| 16025 | If things change they become different - but then no one thing undergoes the change! [Gallois] |
| Full Idea: If things really change, there can't literally be one thing before and after the change. However, if there isn't one thing before and after the change, then no thing has really undergone any change. | |
| From: André Gallois (Identity over Time [2011], Intro) | |
| A reaction: [He cites Copi for this way of expressing the problem of identity through change] There is an obvious simple ambiguity about 'change' in ordinary English. A change of property isn't a change of object. Painting a red ball blue isn't swapping it. |
| 16026 | 4D: time is space-like; a thing is its history; past and future are real; or things extend in time [Gallois] |
| Full Idea: We have four versions of Four-Dimensionalism: the relativistic view that time is space-like; a persisting thing is identical with its history (so objects are events); past and future are equally real; or (Lewis) things extend in time, with temporal parts. | |
| From: André Gallois (Identity over Time [2011], §2.5) | |
| A reaction: Broad proposed the second one. I prefer 3-D: at any given time a thing is wholly present. At another time it is wholly present despite having changed. It is ridiculous to think that small changes destroy identity. We acquire identity by dying?? |
| 16027 | If two things are equal, each side involves a necessity, so the equality is necessary [Gallois] |
| Full Idea: The necessity of identity: a=b; □(a=a); so something necessarily = a; so something necessarily must equal b; so □(a=b). [A summary of the argument of Marcus and Kripke] | |
| From: André Gallois (Identity over Time [2011], §3) | |
| A reaction: [Lowe 1982 offered a response] The conclusion seems reasonable. If two things are mistakenly thought to be different, but turn out to be one thing, that one thing could not possibly be two things. In no world is one thing two things! |
| 5833 | Education is the greatest of human goods [Xenophon] |
| Full Idea: Education is the greatest of human goods. | |
| From: Xenophon (Apology of Socrates [c.392 BCE], 22) | |
| A reaction: Of course, one might ask what education is for, and arrive at a greater good. If you ask what is the greatest good which a society can provide for you, or which you can give to your children, this seems to me a good answer. |
| 21236 | Instead of gravitational force, we now have a pervasive gravitational field [Farmelo] |
| Full Idea: Physics replaced the notion that bodies exert gravitational force on each other by the more effective picture that the bodies in the universe give rise to a pervasive gravitational field which exerts a force on each particle. | |
| From: Graham Farmelo (The Strangest Man [2009], 08) | |
| A reaction: This still uses the word 'force'. I sometimes get the impression that gravity is the curvature of space, but gravity needs more. Which direction along the curvature are particles attracted? The bottom line is the power of the bodies. |
| 21235 | The Schrödinger waves are just the maths of transforming energy values to positions [Farmelo] |
| Full Idea: Dirac showed that the Schrödinger waves were simply the mathematical quantities involved in transforming the description of a quantum based on its energy values to one based on possible values of its position. | |
| From: Graham Farmelo (The Strangest Man [2009], 08) | |
| A reaction: Does this eliminate actual physical 'waves' from the theory? |
| 21234 | Experiments show that fundamental particles of one type are identical [Farmelo] |
| Full Idea: It is an established experimental fact ...that every single fundamental particle in the universe is the same and identical to all other particles of the same type. | |
| From: Graham Farmelo (The Strangest Man [2009], 07) | |
| A reaction: A loud groan is heard from the tomb of Leibniz. I'm unclear how experiments can establish this. If electrons have internal structure (which is not ruled out) then uniformity is highly unlikely. |