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Vienna TEs (2018) Examples & Taxonomy July 2. Is space infinite?. Lucretius, De Rerum Natura Typical TE: Set things up observe what happens draw conclusion Fallible. Definition needed?. No.
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Is space infinite? • Lucretius, De Rerum Natura • Typical TE: • Set things up • observe what happens • draw conclusion • Fallible
Definition needed? • No. • We can argue about important things without a definition, eg, religion, democracy, realism. “I know pornography when I see it” • A lose characterization will do: • we imagine (usually visualize) a situation • we see what happens • then we draw some conclusion
Being hypothetical (or counter-factual) is not enough. TEs are a visualizable subset of counterfactuals. • A TE might be actually performable or it might be practically impossible; this does not seem to matter. • Similar to a real experiment – but different in some respects • Joke: “Putnam fired by Harvard for fudging his TEs. The liquid on Twin Earth was actually H2O, not XYZ.” • This is revealing: We can lie about results of real experiments (eg, patchwork mouse), but not about TEs (at least not in the same way). • We passively receive results of real experiments, but must be active in understanding a TE.
Newton’s bucket Is space absolute or relational? Tension in cord
Einstein’s elevator Does light bend in a gravitational field?
Without experiment, I am sure that the effect will happen as I tell you, because it must happen that way. L H H+L Galileo on free fall Do bodies fall at different rates?
Galileo’s Reasoning • Aristotle and common sense claim: H > L. • Thus, H+L > H • But, H > H+L • This is a contradiction. • Galileo’s resolution: H = L = H+L. • In other words, all bodies fall at the same rate, regardless of their weight.
Taxonomy First division of TEs: Positive (or constructive) vs Negative (or destructive) • Positive TEs establish or support some theory • Negative TEs destroy or undermine some theory
Negative/Destructive TEs • Some negative TEs show that a theory is self-contradictory or conflicts with other well-established theories. • Einstein chases a light beam • Schrödinger’s cat
Some negative TEs show (often by means of a conceptual distinction) that an important conclusion does not follow. (A bit like showing invalidity.) Poincaré’s disk counter to Lucretius’s argument for infinite space Thompson’s violinist right to life ≠ right to what is needed for life Searle’s Chinese room following algorithm ≠ understanding
Thomson’s violinist • Sick violinist (who has a right to life) is hooked up to YOU. • You are not morally obliged to remain attached. • Thus, right to life does not equal right to what is need to sustain life (this is the destructive part; the inference to the conclusion is fairly straightforward). • Thus, anti-abortion argument is refuted.
Poincaré’s disk universe • This example was aimed at certain views about geometry. However, it works very well against Lucretius’s TE to show that space is infinite. • Bug people are on a 2-dimensional disk • Centre of disk has (something like) temperature T, and elsewhere it is T(R2 – r2); thus, it is 0 degrees at the edge. (R = radius of disk, r = distance from centre) • Measuring rod (and everything else) contracts as temperature decreases; hence has 0 length at edge. • In this universe, the measured distance from any point to the edge, as given in their experience, is infinite. • They would never encounter an edge to space (just as in the Lucretius TE). • However, their space is finite. • Upshot: The conclusion of infinite space does not follow from the fact that a spear would pass through any alleged edge of space.
Some negative TEs are what I’ll call “Counter TEs”. They attack another TE and they focus on the phenomenon of the target TE. Galileo’s reply to Aristotelians on possibility of the earth moving Mach’s reply to Newton’s absolute space Dennett’s reply to Jackson’s anti-physicalism
Galileo on the moving earth Common Aristotelian claim: The earth doesn’t move. The justification is based on a TE. If the earth did move, a dropped object would fall behind as we move along, it would not fall straight down. But, as a matter of fact, it does fall straight down. Thus, the earth does not move. Galileo argued against this with a counter TE: Shut yourself up with some friend in the main cabin below decks on some large ship, and have with you there some flies, butterflies and other small flying animals. Have a large bowl of water with some fish in it; hang up a bottle that empties drop by drop into a wide vessel beneath it. With the ship standing still, observe carefully how the little animals fly with equal speed to all sides of the cabin. The fish swim indifferently in all directions; the drop falls into the vessel beneath; and, in throwing something to your friend, you need throw no more strongly in one direction than another, the distances being equal; jumping with your feet together, you pass equal spaces in every direction. When you have observed all these things carefully (though there is no doubt that when the ship is standing still everything must happen in this way), have the ship proceed with any speed you like, so long as the motion is uniform and not fluctuating this way and that. You will discover not the least change in all the effects named, nor could you tell from any of them whether the ship was moving or standing still. (Dialogo 186f) Upshot: whether the earth is moving or not, things would look the same. (This is the principle of relativity.) So, the Aristotelian TE is wrong -- the earth might be moving.
Jackson’s brilliant scientist Mary • Mary learns all physical facts in a black and white environment • When she steps out of lab for first time she comes to know something new — what it’s like to experience red, etc. • Thus, something to be known in addition to the physical facts • Thus, physicalism is wrong
Positive/Constructive TEs • Many types (you could probably add more) • Direct • Mediative • Conjectural
Taxonomy TE Destructive Constructive Counter TEs: Galileo- Schrodinger’s Direct Mediative Conjectural Mach-Newton Aristotle cat Steven Newton Ship of Theseus (1st part) Galileo on falling moon (2nd part)
Mediative • These help us to see the consequences of a theory. They are not necessary to the development of the theory, but they facilitate understanding. Often they serve only a pedagogical role. • Newton on centripetal motion • Maxwell on entropy reversal
Conjectural TEs • The main idea is that a phenomenon is established in the TEs, then a theory is conjectured to explain that phenomena. • Newton’s bucket • Mach’s reply is not aimed at Newton’s explanation; he attacks the phenomenon. • Sklar’s reply is; he attacks the explanation. • Ship of Theseus • Sets up problem of identity, but doesn’t resolve it
Direct TEs • In these cases a TE directly establishes a new theory. • Steven’s statics example • Einstein’s elevator
Taxonomy TEs Destructive Constructive Counter TEs: Galileo- Schrodinger’s Direct Mediative Conjectural Mach-Newton Aristotle cat Steven Newton Ship of Theseus (1st part) Galileo- on falling moon Aristotle (2nd part)
Mixed cases • Some TEs fall under more than one category. • Galileo on falling bodies. • First, it refutes Aristotle’s theory and second, establishes a new one. It is simultaneously destructive and constructive. • Mixed cases such as Galileo’s will be important later.
The Big Questions • The epistemic problem: How is it possible that just by thinking we can learn something new? (Maybe we can’t, so why does it seem we can?) • The classification problem: What are the different ways in which TEs work? (Other taxonomies are possible.) • The discipline problem (1): Why are there so many TEs in physics and philosophy, but very few in anthropology or chemistry? • The discipline problem (2): Is there a unified account of philosophy and science TEs? • The literature problem: Are novels, etc. a form of TE?
