8 ideas
17743 | De Morgan introduced a 'universe of discourse', to replace Boole's universe of 'all things' [De Morgan, by Walicki] |
Full Idea: In 1846 De Morgan introduced the enormously influential notion of a possibly arbitrary and stipulated 'universe of discourse'. It replaced Boole's original - and metaphysically a bit suspect - universe of 'all things'. | |
From: report of Augustus De Morgan (works [1846]) by Michal Walicki - Introduction to Mathematical Logic History D.1.1 | |
A reaction: This not only brings formal logic under control, but also reflects normal talk, because there is always an explicit or implicit domain of discourse when we talk. Of virtually any conversation, you can say what it is 'about'. |
15148 | Powers give explanations, without being necessary for some class membership [Chakravartty] |
Full Idea: Powers explain behaviours regardless of whether they are necessary for membership in a particular class of things. | |
From: Anjan Chakravarrty (Inessential Aristotle: Powers without Essences [2012], 3) | |
A reaction: This seems right, and is important for driving a wedge between powers and essences. If there are essences, they are not simply some bunch of powers. |
15145 | A kind essence is the necessary and sufficient properties for membership of a class [Chakravartty] |
Full Idea: The modern concept of a kind essence is a set of intrinsic properties that are individually necessary and jointly sufficient for the membership of something in a class of things, or 'kind'. | |
From: Anjan Chakravarrty (Inessential Aristotle: Powers without Essences [2012], 2) | |
A reaction: I am always struck by the problem that the kind itself is constructed from the individuals, so circularity always seems to loom. |
15147 | Cluster kinds are explained simply by sharing some properties, not by an 'essence' [Chakravartty] |
Full Idea: The fact that members of some cluster kinds are subjects of causal generalizations reflects the degree to which they share causally efficacious properties, not the fact that they may be composed of essence kinds per se. | |
From: Anjan Chakravarrty (Inessential Aristotle: Powers without Essences [2012], 2) | |
A reaction: I think this is right. I am a fan of individual essences, but not of kind essences. I take kinds, and kind explanations, to be straightforward inductive generalisations from individuals. Extreme stabilities give the illusion of a kind essence. |
15144 | Explanation of causal phenomena concerns essential kinds - but also lack of them [Chakravartty] |
Full Idea: Scientific practices such as prediction and explanation regarding causal phenomena are concerned not merely with kinds having essences, but also with kinds lacking them. | |
From: Anjan Chakravarrty (Inessential Aristotle: Powers without Essences [2012], 1) | |
A reaction: Not quite clear what he has in mind, but explanation should certainly involve a coherent picture, and not just the citation of some underlying causal mechanism. |
7903 | The six perfections are giving, morality, patience, vigour, meditation, and wisdom [Nagarjuna] |
Full Idea: The six perfections are of giving, morality, patience, vigour, meditation, and wisdom. | |
From: Nagarjuna (Mahaprajnaparamitashastra [c.120], 88) | |
A reaction: What is 'morality', if giving is not part of it? I like patience and vigour being two of the virtues, which immediately implies an Aristotelian mean (which is always what is 'appropriate'). |
15146 | Some kinds, such as electrons, have essences, but 'cluster kinds' do not [Chakravartty] |
Full Idea: Many of the kinds we theorize about and experiment on today simply do not have essences. We can distinguish 'essence kinds', such as electrons, and 'cluster kinds', such as biological species. | |
From: Anjan Chakravarrty (Inessential Aristotle: Powers without Essences [2012], 2) | |
A reaction: This is an important point for essentialists. He offers a strict criterion, in Idea 15145, for mind membership, but we might allow species to have essences by just relaxing the criteria a bit, and acknowledging some vagueness, especially over time. |
15151 | Many causal laws do not refer to kinds, but only to properties [Chakravartty] |
Full Idea: Causal laws often do not make reference to kinds of objects at all, but rather summarize relations between quantitative, causally efficacious properties of objects. | |
From: Anjan Chakravarrty (Inessential Aristotle: Powers without Essences [2012], 3) | |
A reaction: This would only be a serious challenge if it was not possible to translate talk of properties into talk of kinds, and vice versa. |