Combining Texts

All the ideas for 'Logical Consequence', 'The Wanderer and his Shadow' and 'The Blank Slate'

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19 ideas

4. Formal Logic / A. Syllogistic Logic / 2. Syllogistic Logic
'Equivocation' is when terms do not mean the same thing in premises and conclusion [Beall/Restall]
     Full Idea: 'Equivocation' is when the terms do not mean the same thing in the premises and in the conclusion.
     From: JC Beall / G Restall (Logical Consequence [2005], Intro)
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Formal logic is invariant under permutations, or devoid of content, or gives the norms for thought [Beall/Restall]
     Full Idea: Logic is purely formal either when it is invariant under permutation of object (Tarski), or when it has totally abstracted away from all contents, or it is the constitutive norms for thought.
     From: JC Beall / G Restall (Logical Consequence [2005], 2)
     A reaction: [compressed] The third account sounds rather woolly, and the second one sounds like a tricky operation, but the first one sounds clear and decisive, so I vote for Tarski.
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence needs either proofs, or absence of counterexamples [Beall/Restall]
     Full Idea: Technical work on logical consequence has either focused on proofs, where validity is the existence of a proof of the conclusions from the premises, or on models, which focus on the absence of counterexamples.
     From: JC Beall / G Restall (Logical Consequence [2005], 3)
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Logical consequence is either necessary truth preservation, or preservation based on interpretation [Beall/Restall]
     Full Idea: Two different views of logical consequence are necessary truth-preservation (based on modelling possible worlds; favoured by Realists), or truth-preservation based on the meanings of the logical vocabulary (differing in various models; for Anti-Realists).
     From: JC Beall / G Restall (Logical Consequence [2005], 2)
     A reaction: Thus Dummett prefers the second view, because the law of excluded middle is optional. My instincts are with the first one.
5. Theory of Logic / B. Logical Consequence / 8. Material Implication
A step is a 'material consequence' if we need contents as well as form [Beall/Restall]
     Full Idea: A logical step is a 'material consequence' and not a formal one, if we need the contents as well as the structure or form.
     From: JC Beall / G Restall (Logical Consequence [2005], 2)
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
A 'logical truth' (or 'tautology', or 'theorem') follows from empty premises [Beall/Restall]
     Full Idea: If a conclusion follows from an empty collection of premises, it is true by logic alone, and is a 'logical truth' (sometimes a 'tautology'), or, in the proof-centred approach, 'theorems'.
     From: JC Beall / G Restall (Logical Consequence [2005], 4)
     A reaction: These truths are written as following from the empty set Φ. They are just implications derived from the axioms and the rules.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
Models are mathematical structures which interpret the non-logical primitives [Beall/Restall]
     Full Idea: Models are abstract mathematical structures that provide possible interpretations for each of the non-logical primitives in a formal language.
     From: JC Beall / G Restall (Logical Consequence [2005], 3)
6. Mathematics / B. Foundations for Mathematics / 2. Proof in Mathematics
Hilbert proofs have simple rules and complex axioms, and natural deduction is the opposite [Beall/Restall]
     Full Idea: There are many proof-systems, the main being Hilbert proofs (with simple rules and complex axioms), or natural deduction systems (with few axioms and many rules, and the rules constitute the meaning of the connectives).
     From: JC Beall / G Restall (Logical Consequence [2005], 3)
7. Existence / C. Structure of Existence / 2. Reduction
Good reductionism connects fields of knowledge, but doesn't replace one with another [Pinker]
     Full Idea: Good reductionism (also called 'hierarchical reductionism') consists not of replacing one field of knowledge with another, but of connecting or unifying them.
     From: Steven Pinker (The Blank Slate [2002], Ch.4)
     A reaction: A nice simple clarification. In this sense I am definitely a reductionist about mind (indeed, about everything). There is nothing threatening to even 'spiritual' understanding by saying that it is connected to the brain.
12. Knowledge Sources / D. Empiricism / 2. Associationism
Connectionists say the mind is a general purpose learning device [Pinker]
     Full Idea: Connectionists do not, of course, believe that the mind is a blank slate, but they do believe in the closest mechanistic equivalent, a general purpose learning device.
     From: Steven Pinker (The Blank Slate [2002], Ch.5)
     A reaction: This shows the closeness of connectionism to Hume's associationism (Idea 2189), which was just a minimal step away from Locke's mind as 'white paper' (Idea 7507). Pinker is defending 'human nature', but connectionism has a point.
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
Is memory stored in protein sequences, neurons, synapses, or synapse-strengths? [Pinker]
     Full Idea: Are memories stored in protein sequences, in new neurons or synapses, or in changes in the strength of existing synapses?
     From: Steven Pinker (The Blank Slate [2002], Ch.5)
     A reaction: This seems to be a neat summary of current neuroscientific thinking about memory. If you are thinking that memory couldn't possibly be so physical, don't forget the mind-boggling number of events involved in each tiny memory. See Idea 6668.
16. Persons / F. Free Will / 5. Against Free Will
Roundworms live successfully with 302 neurons, so human freedom comes from our trillions [Pinker]
     Full Idea: The roundworm only has 959 cells, and 302 neurons in a fixed wiring diagram; it eats, mates, approaches and avoids certain smells, and that's about it. This makes it obvious that human 'free' behaviour comes from our complex biological makeup.
     From: Steven Pinker (The Blank Slate [2002], Ch.5)
     A reaction: I find this a persuasive example. Three hundred trillion neurons cannot possibly produce behaviour which is more than broadly predictable, and then it is the environment and culture that make it predictable, not the biology.
17. Mind and Body / E. Mind as Physical / 4. Connectionism
Neural networks can generalise their training, e.g. truths about tigers apply mostly to lions [Pinker]
     Full Idea: The appeal of neural networks is that they automatically generalize their training to similar new items. If one has been trained to think tigers eat frosted flakes, it will generalise that lions do too, because it knows tigers as sets of features.
     From: Steven Pinker (The Blank Slate [2002], Ch.5)
     A reaction: This certainly is appealing, because it offers a mechanistic account of abstraction and universals, which everyone agrees are central to proper thinking.
There are five types of reasoning that seem beyond connectionist systems [Pinker, by PG]
     Full Idea: Connectionist networks have difficulty with the kind/individual distinction (ducks/this duck), with compositionality (relations), with quantification (reference of 'all'), with recursion (embedded thoughts), and the categorical reasoning (exceptions).
     From: report of Steven Pinker (The Blank Slate [2002], Ch.5) by PG - Db (ideas)
     A reaction: [Read Pinker p.80!] These are essentially all the more sophisticated aspects of logical reasoning that Pinker can think of. Personally I would be reluctant to say a priori that connectionism couldn't cope with these things, just because they seem tough.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Many think that accepting human nature is to accept innumerable evils [Pinker]
     Full Idea: To acknowledge human nature, many think, is to endorse racism, sexism, war, greed, genocide, nihilism, reactionary politics, and neglect of children and the disadvantaged.
     From: Steven Pinker (The Blank Slate [2002], Pref)
     A reaction: The point is that modern liberal thinking says everything is nurture (which can be changed), not nature (which can't). Virtue theory, of which I am a fan, requires a concept of human nature, as the thing which can attain excellence in its function.
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / b. Limited purposes
The end need not be the goal, as in the playing of a melody (and yet it must be completed) [Nietzsche]
     Full Idea: Not every end is the goal; the end of a melody is not its goal; and yet: as long as the melody has not reached its end, it also hasn't reached its goal. A parable.
     From: Friedrich Nietzsche (The Wanderer and his Shadow [1880], §204)
     A reaction: A nice message for Aristotle, that there is no simple separation of ends and means.
27. Natural Reality / G. Biology / 2. Life
In 1828, the stuff of life was shown to be ordinary chemistry, not a magic gel [Pinker]
     Full Idea: In 1828 Friedrich Wöhler showed [by synthesising urea in the laboratory] that the stuff of life is not a magical, pulsating gel, but ordinary compounds following the laws of chemistry.
     From: Steven Pinker (The Blank Slate [2002], Ch.3)
     A reaction: Wöhler synthesised urea in the laboratory.
27. Natural Reality / G. Biology / 3. Evolution
Intelligent Design says that every unexplained phenomenon must be design, by default [Pinker]
     Full Idea: The originator of 'intelligent design' (the biochemist Michael Behe) takes every phenomenon whose evolutionary history has not yet been figured out, and chalks it up to design by default.
     From: Steven Pinker (The Blank Slate [2002], Ch.7)
     A reaction: This seems to summarise the strategy very nicely. The theory essentially exploits the 'wow!' factor. The bigger the wow! the more likely it is that it was created by God. But research has been eroding our wows steadily for four hundred years.
All the evidence says evolution is cruel and wasteful, not intelligent [Pinker]
     Full Idea: The overwhelming evidence is that the process of evolution, far from being intelligent and purposeful, is wasteful and cruel.
     From: Steven Pinker (The Blank Slate [2002], Ch.7)
     A reaction: This is why opponents should reject evolution totally, rather than compromise with it. Stick to a 6000-year-old world, fossils sent to test our faith, and species created in a flash (with no pain or waste).