13 ideas
14235 | Saying 'they can become a set' is a tautology, because reference to 'they' implies a collection [Cargile] |
Full Idea: If the rule is asserted 'Given any well-determined objects, they can be collected into a set by an application of the 'set of' operation', then on the usual account of 'they' this is a tautology. Collection comes automatically with this form of reference. | |
From: James Cargile (Paradoxes: Form and Predication [1979], p.115), quoted by Oliver,A/Smiley,T - What are Sets and What are they For? Intro | |
A reaction: Is this a problem? Given they are well-determined (presumably implying countable) there just is a set of them. That's what set theory is, I thought. Of course, the iterative view talks of 'constructing' the sets, but the construction looks unstoppable. |
17471 | Using mechanisms as explanatory schemes began in chemistry [Weisberg/Needham/Hendry] |
Full Idea: The production of mechanisms as explanatory schemes finds its original home in chemistry. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 5.1) | |
A reaction: This is as opposed to mechanisms in biology or neuroscience, which come later. |
17472 | Thick mechanisms map whole reactions, and thin mechanism chart the steps [Weisberg/Needham/Hendry] |
Full Idea: In chemistry the 'thick' notion of a mechanism traces out positions of electrons and atomic cores, and correlates them with energies, showing the whole reaction. 'Thin' mechanisms focus on a discrete set of intermediate steps. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 5.1) |
6005 | Animals are dangerous and nourishing, and can't form contracts of justice [Hermarchus, by Sedley] |
Full Idea: Hermarchus said that animal killing is justified by considerations of human safety and nourishment and by animals' inability to form contractual relations of justice with us. | |
From: report of Hermarchus (fragments/reports [c.270 BCE]) by David A. Sedley - Hermarchus | |
A reaction: Could the last argument be used to justify torturing animals? Or could we eat a human who was too brain-damaged to form contracts? |
17465 | Lavoisier's elements included four types of earth [Weisberg/Needham/Hendry] |
Full Idea: Four types of earth found a place on Lavoisier's list of elements. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 1.2) | |
A reaction: A nice intermediate point between the ancient Greek and the modern view of earth. |
17469 | 'H2O' just gives the element proportions, not the microstructure [Weisberg/Needham/Hendry] |
Full Idea: 'H2O' is not a description of any microstructure. It is a compositional formula, describing the combining proportions of hydrogen and oxygen to make water. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 4.5) |
17468 | Over 100,000,000 compounds have been discovered or synthesised [Weisberg/Needham/Hendry] |
Full Idea: There are well over 100,000,000 chemical compounds that have been discovered or synthesised, all of which have been formally characterised. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 4.3) |
17470 | Water molecules dissociate, and form large polymers, explaining its properties [Weisberg/Needham/Hendry] |
Full Idea: Water's structure cannot simply be described as a collection of individual molecules. There is a continual dissociation of H2O molecules into hydrogen and hydroxide ions; they former larger polymeric species, explaining conductivity, melting and boiling. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 4.5) | |
A reaction: [compressed] If philosophers try to state the 'essence of water', they had better not be too glib about it. |
17473 | It is unlikely that chemistry will ever be reduced to physics [Weisberg/Needham/Hendry] |
Full Idea: Most philosophers believe chemistry has not been reduced to physics nor is it likely to be. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 6) | |
A reaction: [Le Poidevin 2007 argues the opposite] That chemical features are actually metaphysically 'emergent' is a rare view, defended by Hendry. The general view is that the concepts are too different, and approximations render it hopeless. |
17474 | Quantum theory won't tell us which structure a set of atoms will form [Weisberg/Needham/Hendry] |
Full Idea: Quantum mechanics cannot tell us why a given collection of atoms will adopt one molecular structure (and set of chemical properties) or the other. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 6.1) | |
A reaction: Presumably it the 'chance' process of how the atoms are thrown together. |
17475 | For temperature to be mean kinetic energy, a state of equilibrium is also required [Weisberg/Needham/Hendry] |
Full Idea: Having a particular average kinetic energy is only a necessary condition for having a given temperature, not a sufficient one, because only gases at equilibrium have a well-defined temperature. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 6.2) | |
A reaction: If you try to pin it all down more precisely, the definition turns out to be circular. |
17467 | Isotopes (such as those of hydrogen) can vary in their rates of chemical reaction [Weisberg/Needham/Hendry] |
Full Idea: There are chemically salient differences among the isotopes, best illustrated by the three isotopes of hydrogen: protium, deuterium and tritium, which show different rates of reaction, making heavy water poisonous where ordinary water is not. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 1.4) | |
A reaction: [They cite Paul Needham 2008] The point is that the isotopes are the natural kinds, rather than the traditional elements. The view is unorthodox, but clearly makes a good point. |
17466 | Mendeleev systematised the elements, and also gave an account of their nature [Weisberg/Needham/Hendry] |
Full Idea: In addition to providing the systematization of the elements used in modern chemistry, Mendeleev also gave an account of the nature of the elements which informs contemporary philosophical understanding. | |
From: Weisberg/Needham/Hendry (Philosophy of Chemistry [2011], 1.3) |