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18. Thought / E. Abstraction / 5. Abstracta by Negation

[defining abstractions by specifying what they are not]

7 ideas
Abstractions lack causes, effects and spatio-temporal locations [Mellor/Oliver]
     Full Idea: Abstract entities (such as sets) are usually understood as lacking causes, effects, and spatio-temporal location.
     From: DH Mellor / A Oliver (Introduction to 'Properties' [1997], §10)
     A reaction: This seems to beg some questions. Has the ideal of 'honour' never caused anything? Young men dream of pure velocity.
Concrete and abstract objects are distinct because the former have causal powers and relations [Lowe]
     Full Idea: Concrete objects possess causal powers and relations, but abstract objects are incapable of having causal powers or relations.
     From: E.J. Lowe (A Survey of Metaphysics [2002], p.368)
     A reaction: Is this an observation or a definition? One might claim that an abstraction (such as a political ideal) can acquire causal power through a conscious mnd.
The centre of mass of the solar system is a non-causal abstract object, despite having a location [Lowe]
     Full Idea: The centre of mass of the solar system seems to lack causal powers, and so is an abstract object, even though it has a location and movement.
     From: E.J. Lowe (A Survey of Metaphysics [2002], p.368)
     A reaction: Nice example, with rich ramifications. Abstraction is deeply tied into our understanding of the physical world, and our concept of identity.
Nowadays abstractions are defined as non-spatial, causally inert things [Rosen]
     Full Idea: If any characterization of the abstract deserves to be regarded as the modern standard one, it is this: an abstract entity is a non-spatial (or non-spatiotemporal) causally inert thing. This view presents a number of perplexities...
     From: Gideon Rosen (Abstract Objects [2001], 'Non-spat')
     A reaction: As indicated in other ideas, the problem is that some abstractions do seem to be located somewhere in space-time, and to have come into existence, and to pass away. I like 'to exist is to have causal powers'. See Ideas 5992 and 8300.
Chess may be abstract, but it has existed in specific space and time [Rosen]
     Full Idea: The natural view of chess is not that it is a non-spatiotemporal mathematical object, but that it was invented at a certain time and place, that it has changed over the years, and so on.
     From: Gideon Rosen (Abstract Objects [2001], 'Non-spat')
     A reaction: This strikes me as being undeniable, and being an incredibly important point. Logicians seem to want to subsume things like games into the highly abstract world of logic and numbers. In fact the direction of explanation should be reversed.
Sets are said to be abstract and non-spatial, but a set of books can be on a shelf [Rosen]
     Full Idea: It is thought that sets are abstract, abstract objects do not exist in space, so sets must not exist in space. But it is not unnatural to say that a set of books is located on a certain shelf in the library.
     From: Gideon Rosen (Abstract Objects [2001], 'Non-spat')
     A reaction: The arguments against non-spatiality of abstractions seem to me to be conclusive. Not being able to assign a location to the cosine function is on a par with not knowing where my thoughts are located in my brain.
Abstractions are imperceptible, non-causal, and non-spatiotemporal (the third explaining the others) [Szabó]
     Full Idea: In current discussions, abstract entities are usually distinguished as 1) in principle imperceptible, 2) incapable of causal interaction, 3) not located in space-time. The first is often explained by the second, which is in turn explained by the third.
     From: Zoltán Gendler Szabó (Nominalism [2003], 2.2)
     A reaction: Szabó concludes by offering 3 as the sole criterion of abstraction. As Lewis points out, the Way of Negation for defining abstracta doesn't tell us very much. Courage may be non-spatiotemporal, but what about Alexander the Great's courage?