35 ideas
| 7113 | Phenomenology assumes that all consciousness is of something [Sartre] |
| Full Idea: The essential principle of phenomenology is that 'all consciousness is consciousness of something'. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (B)) | |
| A reaction: This idea is found well before Husserl, in Schopenhauer (Idea 4166). It seems to contradict a thought such as Locke's (Idea 1202), that self-awareness is a separate and distinct criterion for personal identity. Sartre gives a nice account. |
| 13838 | A decent modern definition should always imply a semantics [Hacking] |
| Full Idea: Today we expect that anything worth calling a definition should imply a semantics. | |
| From: Ian Hacking (What is Logic? [1979], §10) | |
| A reaction: He compares this with Gentzen 1935, who was attempting purely syntactic definitions of the logical connectives. |
| 13833 | 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking] |
| Full Idea: 'Dilution' (or 'Thinning') provides an essential contrast between deductive and inductive reasoning; for the introduction of new premises may spoil an inductive inference. | |
| From: Ian Hacking (What is Logic? [1979], §06.2) | |
| A reaction: That is, inductive logic (if there is such a thing) is clearly non-monotonic, whereas classical inductive logic is monotonic. |
| 13834 | Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking] |
| Full Idea: If A |- B and B |- C, then A |- C. This generalises to: If Γ|-A,Θ and Γ,A |- Θ, then Γ |- Θ. Gentzen called this 'cut'. It is the transitivity of a deduction. | |
| From: Ian Hacking (What is Logic? [1979], §06.3) | |
| A reaction: I read the generalisation as 'If A can be either a premise or a conclusion, you can bypass it'. The first version is just transitivity (which by-passes the middle step). |
| 13835 | Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking] |
| Full Idea: Only the cut rule can have a conclusion that is less complex than its premises. Hence when cut is not used, a derivation is quite literally constructive, building up from components. Any theorem obtained by cut can be obtained without it. | |
| From: Ian Hacking (What is Logic? [1979], §08) |
| 13845 | The various logics are abstractions made from terms like 'if...then' in English [Hacking] |
| Full Idea: I don't believe English is by nature classical or intuitionistic etc. These are abstractions made by logicians. Logicians attend to numerous different objects that might be served by 'If...then', like material conditional, strict or relevant implication. | |
| From: Ian Hacking (What is Logic? [1979], §15) | |
| A reaction: The idea that they are 'abstractions' is close to my heart. Abstractions from what? Surely 'if...then' has a standard character when employed in normal conversation? |
| 13840 | First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking] |
| Full Idea: First-order logic is the strongest complete compact theory with a Löwenheim-Skolem theorem. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13844 | A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking] |
| Full Idea: Henkin proved that there is no first-order treatment of branching quantifiers, which do not seem to involve any idea that is fundamentally different from ordinary quantification. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: See Hacking for an example of branching quantifiers. Hacking is impressed by this as a real limitation of the first-order logic which he generally favours. |
| 13842 | Second-order completeness seems to need intensional entities and possible worlds [Hacking] |
| Full Idea: Second-order logic has no chance of a completeness theorem unless one ventures into intensional entities and possible worlds. | |
| From: Ian Hacking (What is Logic? [1979], §13) |
| 13837 | With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking] |
| Full Idea: My doctrine is that the peculiarity of the logical constants resides precisely in that given a certain pure notion of truth and consequence, all the desirable semantic properties of the constants are determined by their syntactic properties. | |
| From: Ian Hacking (What is Logic? [1979], §09) | |
| A reaction: He opposes this to Peacocke 1976, who claims that the logical connectives are essentially semantic in character, concerned with the preservation of truth. |
| 13839 | Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking] |
| Full Idea: For some purposes the variables of first-order logic can be regarded as prepositions and place-holders that could in principle be dispensed with, say by a system of arrows indicating what places fall in the scope of which quantifier. | |
| From: Ian Hacking (What is Logic? [1979], §11) | |
| A reaction: I tend to think of variables as either pronouns, or as definite descriptions, or as temporary names, but not as prepositions. Must address this new idea... |
| 13843 | If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking] |
| Full Idea: A Löwenheim-Skolem theorem holds for anything which, on my delineation, is a logic. | |
| From: Ian Hacking (What is Logic? [1979], §13) | |
| A reaction: I take this to be an unusually conservative view. Shapiro is the chap who can give you an alternative view of these things, or Boolos. |
| 7112 | The Cogito depends on a second-order experience, of being conscious of consciousness [Sartre] |
| Full Idea: We must remember that all authors who have described the Cogito have presented it as a reflective operation, i.e. as second-order. This Cogito is performed by a consciousness directed towards consciousness, which takes consciousness as its object. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (B)) | |
| A reaction: Sartre is raising the nice question of whether the Cogito still works for first-order consciousness, which attends totally to external objects. He claims that it doesn't. Contrast Russell, who says (Idea 5380) that it only works when it is first-order! |
| 7114 | The consciousness that says 'I think' is not the consciousness that thinks [Sartre] |
| Full Idea: The consciousness that says 'I think' is precisely not the consciousness that thinks. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (B)) | |
| A reaction: All parties seem to be agreed that if we are going to introspect in search of our own ego, we must distinguish between the mental act of instrospection and the mental act of applying the mind to the world. Each gives a different result. |
| 7119 | Is the Cogito reporting an immediate experience of doubting, or the whole enterprise of doubting? [Sartre] |
| Full Idea: When Descartes says 'I doubt therefore I am', is he talking about the spontaneous doubt that reflective consciousness grasps in its instantaneous character, or is he talking of the enterprise of doubting? This ambiguity can lead to serious errors. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], II (B)) | |
| A reaction: Interesting. The obvious response is that it is about the immediate experience, but that leads to the problem of an instantaneous ego, which can't be justified over time. The 'enterprise' gives an enduring ego, but it is a more intellectual concept. |
| 8793 | If observation is knowledge, it is not just an experience; it is a justification in the space of reasons [Sellars] |
| Full Idea: In characterizing an observational episode or state as 'knowing', we are not giving an empirical description of it; we are placing it in the logical space of reasons, of justifying and being able to justify what one says. | |
| From: Wilfrid Sellars (Does Emp.Knowledge have Foundation? [1956], p.123) | |
| A reaction: McDowell has made the Kantian phrase 'the logical space of reasons' very popular. This is a very nice statement of the internalist view of justification, with which I sympathise more and more. It is a rationalist coherentist view. It needn't be mystical! |
| 8792 | Observations like 'this is green' presuppose truths about what is a reliable symptom of what [Sellars] |
| Full Idea: Observational knowledge of any particular fact, e.g. that this is green, presupposes that one knows general facts of the form 'X is a reliable symptom of Y'. | |
| From: Wilfrid Sellars (Does Emp.Knowledge have Foundation? [1956], p.123) | |
| A reaction: This is a nicely observed version of the regress problem with justification. I would guess that foundationalists would simply deny that this further knowledge is required; 'this is green' arises out of the experience, but it is not an inference. |
| 7122 | We can never, even in principle, grasp other minds, because the Ego is self-conceiving [Sartre] |
| Full Idea: The Ego can be conceived only through itself and this is why we cannot grasp the consciousness of another (for this reason alone, and not because bodies separate us). | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], II (D)) | |
| A reaction: Interesting. This makes telepathy a logical impossibility, and the body the only possible route for the communication between two minds. But, is Sartre is right, how do bodily events penetrate the inturned world of the Ego? |
| 7125 | A consciousness can conceive of no other consciousness than itself [Sartre] |
| Full Idea: A consciousness can conceive of no other consciousness than itself. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], Conc (1)) | |
| A reaction: This is why we don't know what it is like to be a bat. This seems right, though it looks like a contingent truth, and yet Sartre seems to offer it as a necessary truth. Can God conceive of my consciousness? |
| 7108 | The eternal truth of 2+2=4 is what gives unity to the mind which regularly thinks it [Sartre] |
| Full Idea: The unity of the thousand active consciousnesses through which I have added two and two to make four, is the transcendent object '2+2=4'. Without the permanence of this eternal truth, it would be impossible to conceive of a real unity of mind. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (A)) | |
| A reaction: This is the germ of externalism, here presented as a Platonic attitude to arithmetic, rather than being about water or gold. He claims that internalist attitudes to unity are fictions. I am inclined to think he is wrong, and that unity is biological. |
| 7111 | Consciousness exists as consciousness of itself [Sartre] |
| Full Idea: The existence of consciousness is an absolute, because consciousness is consciousness of itself; the type of existence that consciousness has is that it is consciousness of itself. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (A)) | |
| A reaction: I find this unconvincing. Anyone analysis the nature of the mind should think as much about animal minds as human minds. It seems obvious to me that there is likely to be an animal consciousness which is entirely of environment and its body. |
| 22226 | Since we are a consciousness, Sartre entirely rejected the unconscious mind [Sartre, by Daigle] |
| Full Idea: Sartre refused, denied and fought against the unconscious. Since we are consciousness, there cannot be such a thing as unconsciousness. | |
| From: report of Jean-Paul Sartre (Transcendence of the Ego [1937]) by Christine Daigle - Jean-Paul Sartre 2.1 | |
| A reaction: The modern view is increasingly opposed to this, as neuroscience and psychology uncover hidden motives etc. Sartre's view is still legitimate, though. An unconscious motive is not more my motive than a law of the land is part of me? |
| 7107 | Intentionality defines, transcends and unites consciousness [Sartre] |
| Full Idea: Consciousness is defined by intentionality. Through intentionality it transcends itself, it unifies itself by going outside itself. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (A)) | |
| A reaction: The standard view for a hundred years was Brentano's idea that intentionality defines the mind. Qualia are the modern rival. If I had to choose I think I would go for intentionality, but they may be naturally and metaphysically inseparable. |
| 7109 | If you think of '2+2=4' as the content of thought, the self must be united transcendentally [Sartre] |
| Full Idea: It is possible that those who think that '2 and 2 make 4' is the content of my representations may be forced to resort to a transcendental and subjective principle of unification - in other words, the I. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (A)) | |
| A reaction: He suggests that thoughts themselves unite the mind, externally. If you think of thoughts as internal, you must resort to a transcendental fiction to unify the mind. Personally I think the mind is inherently unified by brain structures. |
| 7106 | The Ego is not formally or materially part of consciousness, but is outside in the world [Sartre] |
| Full Idea: I should like to show here that the Ego is neither formally nor materially in consciousness; it is outside, in the world; it is a being in the world, like the Ego of another. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], Intro) | |
| A reaction: This idea is the germ of what has got modern externalists about the mind (see quotations from Mark Rowlands) interested in Sartre. Personally I think he is wrong, and the Ego is a part of consciousness. It doesn't, though, have sharp boundaries. |
| 7117 | How could two I's, the reflective and the reflected, communicate with each other? [Sartre] |
| Full Idea: If the 'I' is part of consciousness, there will be two I's: the reflective and the reflected. ...but it is unacceptable for any communication to be established between the reflective I and the reflected I, if they are real elements of consciousness. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (B)) | |
| A reaction: If we accept that there are two orders of consciousness (reflective, about itself, and reflected, about the world) it seems reasonable to say that there cannot be an 'I' in both of them. A nice, and intriguing, argument. |
| 7123 | Knowing yourself requires an exterior viewpoint, which is necessarily false [Sartre] |
| Full Idea: 'To know oneself well' is inevitably to look at oneself from the point of view of someone else, in other words from a point of view that is necessarily false. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], II (D)) | |
| A reaction: (This is because the Ego cannot be known from the outside). I agree with Russell that the self is most evident when we are engaged with the world, which implies that you can only acquire self-knowledge by studying those engagements. |
| 22225 | My ego is more intimate to me, but not more certain than other egos [Sartre] |
| Full Idea: My I, in efffect, is no more certain for consciousness than the I of other men. It is only more intimate. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], p.104), quoted by Christine Daigle - Jean-Paul Sartre 2.1 | |
| A reaction: Not sure how to assess this. Other people seem just as real as I do, when I encounter them, as friend or as foe. And in dealing with them we act as if dealing with their Self (rather than their legs, say). So this idea seems a good one. |
| 7124 | The Ego never appears except when we are not looking for it [Sartre] |
| Full Idea: The Ego never appears except when we are not looking for it. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], II (D)) | |
| A reaction: He denies that we know the Ego when engaged with the world, and agrees with Hume that the ego can't be directly known. All that is left is this, which seems to be introspection 'out of the corner of your eye'. Not persuasive. |
| 7116 | When we are unreflective (as when chasing a tram) there is no 'I' [Sartre] |
| Full Idea: There is no 'I' on the unreflected level. When I run after a tram, ...there is no I. There is a consciousness of the tram-needing-to-be-caught, and a non-positional consciousness of consciousness. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (B)) | |
| A reaction: Russell (Idea 5380) says exactly the opposite. My sympathies are more with Russell. I don't just focus on the tram, I focus on the relation between myself and the tram, and that includes my need to catch it, as well as my body. |
| 7120 | It is theoretically possible that the Ego consists entirely of false memories [Sartre] |
| Full Idea: One cannot rule out the metaphysical hypothesis that my Ego is not composed of elements that have existed in reality (ten years or one second ago), but is merely constituted by false memories. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], II (D)) | |
| A reaction: (He mentions the evil demon as a source). The problem that false memories (such as George IV 'remembering' he was at Waterloo, when he wasn't) is well known. But this raises the possibility of all memories being false, yet constituting the person. |
| 7110 | If the 'I' is transcendental, it unnecessarily splits consciousness in two [Sartre] |
| Full Idea: The superfluous transcendental 'I' is actually a hindrance. If it existed, it would violently separate consciousness from itself, it would divide it, slicing through consciousness like an opaque blade. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (A)) | |
| A reaction: I see no a priori reason why consciousness should not be split in two, if that's how it is. Personally I am happy with a fairly traditional Cartesian view, that the self is the will and understanding, and the rest of consciousness is its working material. |
| 7115 | Maybe it is the act of reflection that brings 'me' into existence [Sartre] |
| Full Idea: Might it not be precisely the reflective act that brings the me into being in reflected consciousness? | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], I (B)) | |
| A reaction: He admits some sort of self a second-order entity, but this is 'transcendental', and essentially an illusion. This elimination of the first-order self clears the way for the existential view, that we can create whatever self we want. I disagree. |
| 7121 | The Ego only appears to reflection, so it is cut off from the World [Sartre] |
| Full Idea: The Ego is an object that appears only to reflection, and is thereby radically cut off from the World. | |
| From: Jean-Paul Sartre (Transcendence of the Ego [1937], II (D)) | |
| A reaction: This is the culmination of Sartre's attack (in 1937) on the Ego, paving the way for the freedom of existentialism. Personally I don't accept this picture of the Ego as a second-order fiction. My Ego is part of my relationship with the World. |
| 8791 | The concept of 'green' involves a battery of other concepts [Sellars] |
| Full Idea: One can only have the concept of green by having a whole battery of concepts of which it is one element. | |
| From: Wilfrid Sellars (Does Emp.Knowledge have Foundation? [1956], p.120) | |
| A reaction: This points in the direction of holism about language and thought, but need not imply it. It might be that concepts have to be learned in small families. It is not clear, though, what is absolutely essential to 'green', except that it indicates colour. |