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All the ideas for '', 'Logical Investigations' and 'Change in View: Principles of Reasoning'

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18 ideas

1. Philosophy / H. Continental Philosophy / 2. Phenomenology
Phenomenology is the science of essences - necessary universal structures for art, representation etc. [Husserl, by Polt]
     Full Idea: For Husserl, phenomenology must seek the essential aspects of phenomena - necessary, universal structures, such as the essence of art or the essence of representation. He sought a science of these essences.
     From: report of Edmund Husserl (Logical Investigations [1900]) by Richard Polt - Heidegger: an introduction 2 'Dilthey'
Bracketing subtracts entailments about external reality from beliefs [Husserl, by Putnam]
     Full Idea: In effect, the device of bracketing subtracts entailments from the ordinary belief locution (the entailments that refer to what is external to the thinker's mind).
     From: report of Edmund Husserl (Logical Investigations [1900]) by Hilary Putnam - Reason, Truth and History Ch.2
     A reaction: This seems to leave phenomenology as pure introspection, or as a phenomenalist description of sense-data. It is also a refusal to explain anything. That sounds quite appealing, like Keats's 'negative capability'.
Phenomenology aims to describe experience directly, rather than by its origins or causes [Husserl, by Mautner]
     Full Idea: Phenomenology, in Husserl, is an attempt to describe our experience directly, as it is, separately from its origins and development, independently of the causal explanations that historians, sociologists or psychologists might give.
     From: report of Edmund Husserl (Logical Investigations [1900]) by Thomas Mautner - Penguin Dictionary of Philosophy p.421
     A reaction: In this simple definition the concept sounds very like the modern popular use of the word 'deconstruction', though that is applied more commonly to cultural artifacts than to actual sense experience.
2. Reason / A. Nature of Reason / 1. On Reason
The rules of reasoning are not the rules of logic [Harman]
     Full Idea: Rules of deduction are rules of deductive argument; they are not rules of inference or reasoning.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 1)
     A reaction: And I have often noticed that good philosophing reasoners and good logicians are frequently not the same people.
If there is a great cost to avoiding inconsistency, we learn to reason our way around it [Harman]
     Full Idea: We sometimes discover our views are inconsistent and do not know how to revise them in order to avoid inconsistency without great cost. The best response may be to keep the inconsistency and try to avoid inferences that exploit it.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2)
     A reaction: Any decent philosopher should face this dilemma regularly. I assume non-philosophers don't compare the different compartments of their beliefs very much. Students of non-monotonic logics are trying to formalise such thinking.
Logic has little relevance to reasoning, except when logical conclusions are immediate [Harman]
     Full Idea: Although logic does not seem specially relevant to reasoning, immediate implication and immediate inconsistency do seem important for reasoning.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2)
     A reaction: Ordinary thinkers can't possibly track complex logical implications, so we have obviously developed strategies for coping. I assume formal logic is contructed from the basic ingredients of the immediate and obvious implications, such as modus ponens.
It is a principle of reasoning not to clutter your mind with trivialities [Harman]
     Full Idea: I am assuming the following principle: Clutter Avoidance - in reasoning, one should not clutter one's mind with trivialities.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2)
     A reaction: I like Harman's interest in the psychology of reasoning. In the world of Frege, it is taboo to talk about psychology.
2. Reason / A. Nature of Reason / 4. Aims of Reason
Implication just accumulates conclusions, but inference may also revise our views [Harman]
     Full Idea: Implication is cumulative, in a way that inference may not be. In argument one accumulates conclusions; things are always added, never subtracted. Reasoned revision, however, can subtract from one's view as well as add.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 1)
     A reaction: This has caught Harman's attention, I think (?), because he is looking for non-monotonic reasoning (i.e. revisable reasoning) within a classical framework. If revision is responding to evidence, the logic can remain conventional.
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
If a sound conclusion comes from two errors that cancel out, the path of the argument must matter [Rumfitt]
     Full Idea: If a designated conclusion follows from the premisses, but the argument involves two howlers which cancel each other out, then the moral is that the path an argument takes from premisses to conclusion does matter to its logical evaluation.
     From: Ian Rumfitt ("Yes" and "No" [2000], II)
     A reaction: The drift of this is that our view of logic should be a little closer to the reasoning of ordinary language, and we should rely a little less on purely formal accounts.
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
Standardly 'and' and 'but' are held to have the same sense by having the same truth table [Rumfitt]
     Full Idea: If 'and' and 'but' really are alike in sense, in what might that likeness consist? Some philosophers of classical logic will reply that they share a sense by virtue of sharing a truth table.
     From: Ian Rumfitt ("Yes" and "No" [2000])
     A reaction: This is the standard view which Rumfitt sets out to challenge.
The sense of a connective comes from primitively obvious rules of inference [Rumfitt]
     Full Idea: A connective will possess the sense that it has by virtue of its competent users' finding certain rules of inference involving it to be primitively obvious.
     From: Ian Rumfitt ("Yes" and "No" [2000], III)
     A reaction: Rumfitt cites Peacocke as endorsing this view, which characterises the logical connectives by their rules of usage rather than by their pure semantic value.
10. Modality / B. Possibility / 6. Probability
The Gambler's Fallacy (ten blacks, so red is due) overemphasises the early part of a sequence [Harman]
     Full Idea: The Gambler's Fallacy says if black has come up ten times in a row, red must be highly probable next time. It overlooks how the impact of an initial run of one color can become more and more insignificant as the sequence gets longer.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 1)
     A reaction: At what point do you decide that the roulette wheel is fixed, rather than that you have fallen for the Gambler's Fallacy? Interestingly, standard induction points to the opposite conclusion. But then you have prior knowledge of the wheel.
High probability premises need not imply high probability conclusions [Harman]
     Full Idea: Propositions that are individually highly probable can have an immediate implication that is not. The fact that one can assign a high probability to P and also to 'if P then Q' is not sufficient reason to assign high probability to Q.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 3)
     A reaction: He cites Kyburg's Lottery Paradox. It is probable that there is a winning ticket, and that this ticket is not it. Thus it is NOT probable that I will win.
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
We strongly desire to believe what is true, even though logic does not require it [Harman]
     Full Idea: Moore's Paradox: one is strongly disposed not to believe both P and that one does not believe that P, while realising that these propositions are perfectly consistent with one another.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 2)
     A reaction: [Where in Moore?] A very nice example of a powerful principle of reasoning which can never be captured in logic.
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
Husserl says we have intellectual intuitions (of categories), as well as of the senses [Husserl, by Velarde-Mayol]
     Full Idea: The novelty of Husserl is to describe that we have intellectual intuitions, intuitions of categories as we have intuitions of sense objects.
     From: report of Edmund Husserl (Logical Investigations [1900], II.VI.24) by Victor Velarde-Mayol - On Husserl 2.4.4
     A reaction: This is 'intuitions' in Kant's sense, of something like direct apprehensions. This idea is an axiom of phenomenology, because all mental life must be bracketed, and not just the sense experience part.
13. Knowledge Criteria / B. Internal Justification / 5. Coherentism / a. Coherence as justification
In revision of belief, we need to keep track of justifications for foundations, but not for coherence [Harman]
     Full Idea: The key issue in belief revision is whether one needs to keep track of one's original justifications for beliefs. What I am calling the 'foundations' theory says yes; what I am calling the 'coherence' theory says no.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 4)
     A reaction: I favour coherence in all things epistemological, and this idea seems to match real life, where I am very confident of many beliefs of which I have forgotten the justification. Harman says coherentists need the justification only when they doubt a belief.
Coherence is intelligible connections, especially one element explaining another [Harman]
     Full Idea: Coherence in a view consists in connections of intelligibility among the elements of the view. Among other things these included explanatory connections, which hold when part of one's view makes it intelligible why some other part should be true.
     From: Gilbert Harman (Change in View: Principles of Reasoning [1986], 7)
     A reaction: Music to my ears. I call myself an 'explanatory empiricist', and embrace a coherence theory of justification. This is the framework within which philosophy should be practised. Harman is our founder, and Paul Thagard our guru.
19. Language / F. Communication / 3. Denial
We learn 'not' along with affirmation, by learning to either affirm or deny a sentence [Rumfitt]
     Full Idea: The standard view is that affirming not-A is more complex than affirming the atomic sentence A itself, with the latter determining its sense. But we could learn 'not' directly, by learning at once how to either affirm A or reject A.
     From: Ian Rumfitt ("Yes" and "No" [2000], IV)
     A reaction: [compressed] This seems fairly anti-Fregean in spirit, because it looks at the psychology of how we learn 'not' as a way of clarifying what we mean by it, rather than just looking at its logical behaviour (and thus giving it a secondary role).