4901
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Truth has to be correspondence to facts, and a match between relations of ideas and relations in the world [Perry]
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Full Idea:
I think knowledge and truth are a matter of correspondence to facts, despite all the energy spent showing the naïveté of this view. The connections of our ideas in our heads correspond to relations in the outside world.
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §8.1)
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A reaction:
Yes. Modern books offer the difficulties of defining 'correspondence', and finding an independent account of 'facts', as conclusive objections, but I say a brain is a truth machine, and it had better be useful. Indefinability doesn't nullify concepts.
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4885
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Identity is a very weak relation, which doesn't require interdefinability, or shared properties [Perry]
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Full Idea:
The truth of "a=b" doesn't require much of 'a' and 'b' other than that there is a single thing to which they both refer. They needn't be interdefinable, or have supervenient properties. In this sense, identity is a very weak relation.
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §1.2)
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A reaction:
Interesting. This is seeing the epistemological aspects of identity. Ontologically, identity must invoke Leibniz's Law, and is the ultimately powerful 'relation'. A given student, and the cause of a crop circle, may APPEAR to be quite different.
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4899
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Possible worlds thinking has clarified the logic of modality, but is problematic in epistemology [Perry]
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Full Idea:
Using possible worlds to model truth-conditions of statements has led to considerable clarity about the logic of modality. Attempts to use the system for epistemic purposes, however, have been plagued by problems.
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §8.1)
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A reaction:
Presumably what lurks behind this is a distinction between what is logically or naturally possible, and what appears to be possible from the perspective of a conscious mind. Is there a possible world in which I can fly?
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4898
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Possible worlds are indices for a language, or concrete realities, or abstract possibilities [Perry]
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Full Idea:
Possible worlds can be thought of as indices for models of the language in question, or as concrete realities (David Lewis), or as abstract ways the world might be (Robert Stalnaker), or in various other ways.
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §8.1)
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A reaction:
I strongly favour the Stalnaker route here. Reducing great metaphysics to mere language I find abhorrent, and I suspect that Lewis was trapped by his commitment to strong empiricism. We must embrace abstractions into our ontology.
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4891
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If epiphenomenalism just says mental events are effects but not causes, it is consistent with physicalism [Perry]
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Full Idea:
Epiphenomenalism is usually considered to be a form of dualism, but if we define it as the doctrine that conscious events are effects but not causes, it appears to be consistent with physicalism.
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §4.2)
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A reaction:
Interesting. The theory was invented to put mind outside physics, and make the closure of physics possible. However, being capable of causing things seems to be a necessary condition for physical objects. An effect in one domain is a cause in another.
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4889
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Although we may classify ideas by content, we individuate them differently, as their content can change [Perry]
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Full Idea:
Although we classify ideas by content for many purposes, we do not individuate them by content. The content of an idea can change.
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §3.2)
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A reaction:
As the compiler of this database, I find this very appealing. The mind works exactly like a database. I have a 'file' (Perry's word) marked "London", the content of which undergoes continual change. I am a database management system.
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4896
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The intension of an expression is a function from possible worlds to an appropriate extension [Perry]
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Full Idea:
In possible-worlds semantics, expressions have intensions, which are functions from possible worlds to appropriate extensions (names to individuals, n-place predicates to n-tuples, and sentences to truth values, built from parts).
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From:
John Perry (Knowledge, Possibility and Consciousness [2001], §8.1)
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A reaction:
Interesting. Perry distinguishes 'referential' (or 'subject matter') content, which is prior to the link to extensions - a link which creates 'reflexive' content. He is keen that they should not become confused. True knowledge is 'situated'.
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8412
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A causal interaction is when two processes intersect, and correlated modifications persist afterwards [Salmon]
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Full Idea:
When two processes intersect, and they undergo correlated modifications which persist after the intersection, I shall say that the intersection is a causal interaction. I take this as a fundamental causal concept.
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From:
Wesley Salmon (Causality: Production and Propagation [1980], §4)
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A reaction:
There may be a problem individuating processes, just as there is for events. I like this approach to causation, which is ontologically sparse, and fits in with the scientific worldview. Change of properties sounds precise, but isn't. Stick to processes.
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8413
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Cause must come first in propagations of causal interactions, but interactions are simultaneous [Salmon]
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Full Idea:
In a typical cause-effect situation (a 'propagation') cause must precede effect, for propagation over a finite time interval is an essential feature. In an 'interaction', an intersection of processes resulting in change, we have simultaneity.
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From:
Wesley Salmon (Causality: Production and Propagation [1980], §8)
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A reaction:
This takes the direction of time as axiomatic, and quite right too. Salmon isn't addressing the real difficulty, though, which is that the resultant laws are usually held to be time-reversible, which is a bit of a puzzle.
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8411
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Instead of localised events, I take enduring and extended processes as basic to causation [Salmon]
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Full Idea:
I propose to approach causality by taking processes rather than events as basic entities. Events are relatively localised in space and time, while processes have much greater temporal duration, and, in many cases, much greater spatial extent.
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From:
Wesley Salmon (Causality: Production and Propagation [1980], §2)
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A reaction:
This strikes me as an incredibly promising proposal, not just in our understanding of causation, but for our general metaphysics and understanding of nature. See Idea 4931, for example. Vague events and processes blend into one another.
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