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All the ideas for 'works', 'Justified Belief as Responsible Belief' and 'First-order Logic, 2nd-order, Completeness'

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18 ideas

2. Reason / A. Nature of Reason / 6. Coherence
Coherentists seek relations among beliefs that are simple, conservative and explanatory [Foley]
     Full Idea: Coherentists try to provide an explication of epistemic rationality in terms of a set of deductive and probabilistic relations among beliefs and properties such as simplicity, conservativeness, and explanatory power.
     From: Richard Foley (Justified Belief as Responsible Belief [2005], p.317)
     A reaction: I have always like the coherentist view of justification, and now I see that this has led me to the question of explanation, which in turn has led me to essentialism. It's all coming together. Watch this space. 'Explanatory' is the key to everything!
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Second-order logic needs the sets, and its consequence has epistemological problems [Rossberg]
     Full Idea: Second-order logic raises doubts because of its ontological commitment to the set-theoretic hierarchy, and the allegedly problematic epistemic status of the second-order consequence relation.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §1)
     A reaction: The 'epistemic' problem is whether you can know the truths, given that the logic is incomplete, and so they cannot all be proved. Rossberg defends second-order logic against the second problem. A third problem is that it may be mathematics.
Henkin semantics has a second domain of predicates and relations (in upper case) [Rossberg]
     Full Idea: Henkin semantics (for second-order logic) specifies a second domain of predicates and relations for the upper case constants and variables.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3)
     A reaction: This second domain is restricted to predicates and relations which are actually instantiated in the model. Second-order logic is complete with this semantics. Cf. Idea 10756.
There are at least seven possible systems of semantics for second-order logic [Rossberg]
     Full Idea: In addition to standard and Henkin semantics for second-order logic, one might also employ substitutional or game-theoretical or topological semantics, or Boolos's plural interpretation, or even a semantics inspired by Lesniewski.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3)
     A reaction: This is helpful in seeing the full picture of what is going on in these logical systems.
5. Theory of Logic / B. Logical Consequence / 2. Types of Consequence
Logical consequence is intuitively semantic, and captured by model theory [Rossberg]
     Full Idea: Logical consequence is intuitively taken to be a semantic notion, ...and it is therefore the formal semantics, i.e. the model theory, that captures logical consequence.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §2)
     A reaction: If you come at the issue from normal speech, this seems right, but if you start thinking about the necessity of logical consequence, that formal rules and proof-theory seem to be the foundation.
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
Γ |- S says S can be deduced from Γ; Γ |= S says a good model for Γ makes S true [Rossberg]
     Full Idea: Deductive consequence, written Γ|-S, is loosely read as 'the sentence S can be deduced from the sentences Γ', and semantic consequence Γ|=S says 'all models that make Γ true make S true as well'.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §2)
     A reaction: We might read |= as 'true in the same model as'. What is the relation, though, between the LHS and the RHS? They seem to be mutually related to some model, but not directly to one another.
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
In proof-theory, logical form is shown by the logical constants [Rossberg]
     Full Idea: A proof-theorist could insist that the logical form of a sentence is exhibited by the logical constants that it contains.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §2)
     A reaction: You have to first get to the formal logical constants, rather than the natural language ones. E.g. what is the truth table for 'but'? There is also the matter of the quantifiers and the domain, and distinguishing real objects and predicates from bogus.
5. Theory of Logic / J. Model Theory in Logic / 1. Logical Models
A model is a domain, and an interpretation assigning objects, predicates, relations etc. [Rossberg]
     Full Idea: A standard model is a set of objects called the 'domain', and an interpretation function, assigning objects in the domain to names, subsets to predicate letters, subsets of the Cartesian product of the domain with itself to binary relation symbols etc.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3)
     A reaction: The model actually specifies which objects have which predicates, and which objects are in which relations. Tarski's account of truth in terms of 'satisfaction' seems to be just a description of those pre-decided facts.
5. Theory of Logic / J. Model Theory in Logic / 2. Isomorphisms
If models of a mathematical theory are all isomorphic, it is 'categorical', with essentially one model [Rossberg]
     Full Idea: A mathematical theory is 'categorical' if, and only if, all of its models are isomorphic. Such a theory then essentially has just one model, the standard one.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3)
     A reaction: So the term 'categorical' is gradually replacing the much-used phrase 'up to isomorphism'.
5. Theory of Logic / K. Features of Logics / 4. Completeness
Completeness can always be achieved by cunning model-design [Rossberg]
     Full Idea: All that should be required to get a semantics relative to which a given deductive system is complete is a sufficiently cunning model-theorist.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §5)
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
A deductive system is only incomplete with respect to a formal semantics [Rossberg]
     Full Idea: No deductive system is semantically incomplete in and of itself; rather a deductive system is incomplete with respect to a specified formal semantics.
     From: Marcus Rossberg (First-order Logic, 2nd-order, Completeness [2004], §3)
     A reaction: This important point indicates that a system might be complete with one semantics and incomplete with another. E.g. second-order logic can be made complete by employing a 'Henkin semantics'.
13. Knowledge Criteria / A. Justification Problems / 3. Internal or External / c. Disjunctivism
Externalists want to understand knowledge, Internalists want to understand justification [Foley]
     Full Idea: Externalists are principally interested in understanding what knowledge is, ..while internalists, by contrast, are principally interested in explicating a sense of justification ..from one's own perspective.
     From: Richard Foley (Justified Belief as Responsible Belief [2005], p.314)
     A reaction: I find this very helpful, since I have a strong bias towards internalism (with a social dimension), and I see now that it is because I am more interested in what a (good) justification is than what some entity in reality called 'knowledge' consists of.
13. Knowledge Criteria / B. Internal Justification / 2. Pragmatic justification
We aren't directly pragmatic about belief, but pragmatic about the deliberation which precedes it [Foley]
     Full Idea: It is rare for pragmatic considerations to influence the rationality of our beliefs in the crass, direct way that Pascal's Wager envisions. Instead, they determine the direction and shape of our investigative and deliberative projects and practices.
     From: Richard Foley (Justified Belief as Responsible Belief [2005], p.320)
     A reaction: [See Idea 6684 for Pascal's Wager] Foley is evidently a full-blown pragmatist (which is bad), but this is nicely put. We can't deny the importance of the amount of effort put into an enquiry. Maybe it is an epistemic duty, rather than a means to an end.
Justification comes from acceptable procedures, given practical constraints [Foley]
     Full Idea: One justifiably believes a proposition if one has an epistemically rational belief that one's procedures with respect to it have been acceptable, given practical limitations, and one's goals.
     From: Richard Foley (Justified Belief as Responsible Belief [2005], p.322)
     A reaction: I quite like this, except that it is too individualistic. My goals, and my standards of acceptability decree whether I know? I don't see the relevance of goals; only a pragmatist would mention such a thing. Standards of acceptability are social.
15. Nature of Minds / B. Features of Minds / 2. Unconscious Mind
Freud treats the unconscious as intentional and hence mental [Freud, by Searle]
     Full Idea: Freud thinks that our unconscious mental states exist as occurrent intrinsic intentional states even when unconscious. Their ontology is that of the mental, even when they are unconscious.
     From: report of Sigmund Freud (works [1900]) by John Searle - The Rediscovery of the Mind Ch. 7.V
     A reaction: Searle states this view in order to attack it. Whether such states are labelled as 'mental' seems uninteresting. Whether unconscious states can be intentional is crucial, and modern scientific understanding of the brain strongly suggest they can.
16. Persons / C. Self-Awareness / 3. Limits of Introspection
Freud and others have shown that we don't know our own beliefs, feelings, motive and attitudes [Freud, by Shoemaker]
     Full Idea: Freud persuaded many that beliefs, wishes and feelings are sometimes unconscious, and even sceptics about Freud acknowledge that there is self-deception about motive and attitudes.
     From: report of Sigmund Freud (works [1900]) by Sydney Shoemaker - Introspection p.396
     A reaction: This seems to me obviously correct. The traditional notion is that the consciousness is the mind, but now it seems obvious that consciousness is only one part of the mind, and maybe even a peripheral (epiphenomenal) part of it.
18. Thought / A. Modes of Thought / 3. Emotions / a. Nature of emotions
Freud said passions are pressures of some flowing hydraulic quantity [Freud, by Solomon]
     Full Idea: Freud argued that the passions in general …were the pressures of a yet unknown 'quantity' (which he simply designated 'Q'). He first thought this flowed through neurones, …and always couched the idea in the language of hydraulics.
     From: report of Sigmund Freud (works [1900]) by Robert C. Solomon - The Passions 3.4
     A reaction: This is the main target of Solomon's criticism, because its imagery has become so widespread. It leads to talk of suppressing emotions, or sublimating them. However, it is not too different from Nietzsche's 'drives' or 'will to power'.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Freud is pessimistic about human nature; it is ambivalent motive and fantasy, rather than reason [Freud, by Murdoch]
     Full Idea: Freud takes a thoroughly pessimistic view of human nature. ...Introspection reveals only the deep tissue of ambivalent motive, and fantasy is a stronger force than reason. Objectivity and unselfishness are not natural to human beings.
     From: report of Sigmund Freud (works [1900], II) by Iris Murdoch - The Sovereignty of Good II
     A reaction: Interesting. His view seems to have coloured the whole of modern culture, reinforced by the hideous irrationality of the Nazis. Adorno and Horkheimer attacking the Enlightenment was the last step in that process.