18 ideas
| 23449 | Interpreting a text is representing it as making sense [Morris,M] |
| Full Idea: Interpreting a text is a matter of making sense of it. And to make sense of a text is to represent it as making sense. | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], Intro.2) | |
| A reaction: 'Making sense' is obviously not a very precise or determinate concept. It is probably better to say that the process is 'trying' to make sense of the text, because most texts don't totally make sense. |
| 18901 | Truthmakers are facts 'of' a domain, not something 'in' the domain [Sommers] |
| Full Idea: A fact is an existential characteristic 'of' the domain; it is not something 'in' the domain. To search for truth-making facts in the world is indeed futile. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Existence') | |
| A reaction: Attacking Austin on truth. Helpful. It is hard to see how a physical object has a mysterious power to 'make' a truth. No energy-transfer seems involved in the making. Animals think true thoughts; I suspect that concerns their mental maps of the world. |
| 18904 | 'Predicable' terms come in charged pairs, with one the negation of the other [Sommers, by Engelbretsen] |
| Full Idea: Sommers took the 'predicable' terms of any language to come in logically charged pairs. Examples might be red/nonred, massive/massless, tied/untied, in the house/not in the house. The idea that terms can be negated was essential for such pairing. | |
| From: report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2 | |
| A reaction: If, as Rumfitt says, we learn affirmation and negation as a single linguistic operation, this would fit well with it, though Rumfitt doubtless (as a fan of classical logic) prefers to negation sentences. |
| 18895 | Logic which maps ordinary reasoning must be transparent, and free of variables [Sommers] |
| Full Idea: What would a 'laws of thought' logic that cast light on natural language deductive thinking be like? Such a logic must be variable-free, conforming to normal syntax, and its modes of reasoning must be transparent, to make them virtually instantaneous. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'How We') | |
| A reaction: This is the main motivation for Fred Sommers's creation of modern term logic. Even if you are up to your neck in modern symbolic logic (which I'm not), you have to find this idea appealing. You can't leave it to the psychologists. |
| 23484 | Bipolarity adds to Bivalence the capacity for both truth values [Morris,M] |
| Full Idea: According to the Principle of Bipolarity, every meaningful sentence must be capable both of being true and of being false. It is not enough merely that every sentence must be either true or false (which is Bivalence). | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], 3D) | |
| A reaction: It is said that early Wittgenstein endorses this. That is, in addition to being true, the sentence must be capable of falsehood (and vice versa). This seems to be flirting with the verification principle. I presume it is 'affirmative' sentences. |
| 18897 | Predicate logic has to spell out that its identity relation '=' is an equivalent relation [Sommers] |
| Full Idea: Because predicate logic contrues identities dyadically, its account of inferences involving identity propositions needs laws or axioms of identity, explicitly asserting that the dyadic realtion in 'x=y' possesses symmetry, reflexivity and transitivity. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Syllogistic') |
| 18893 | Translating into quantificational idiom offers no clues as to how ordinary thinkers reason [Sommers] |
| Full Idea: Modern predicate logic's methods of justification, which involve translation into an artificial quantificational idiom, offer no clues to how the average person, knowing no logic and adhering to the vernacular, is so logically adept. | |
| From: Fred Sommers (Intellectual Autobiography [2005], Intro) | |
| A reaction: Of course, people are very logically adept when the argument is simple (because, I guess, they can test it against the world), but not at all good when the reasoning becomes more complex. We do, though, reason in ordinary natural language. |
| 18903 | Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen] |
| Full Idea: If there is one idea that is the keystone of the edifice that constitutes Sommers's united philosophy it is that terms are the linguistic entities subject to negation in the most basic sense. It is a very old idea, tending to be rejected in modern times. | |
| From: report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2 | |
| A reaction: Negation in modern logic is an operator applied to sentences, typically writing '¬Fa', which denies that F is predicated of a, with Fa being an atomic sentence. Do we say 'not(Stan is happy)', or 'not-Stan is happy', or 'Stan is not-happy'? Third one? |
| 18894 | Predicates form a hierarchy, from the most general, down to names at the bottom [Sommers] |
| Full Idea: We organise our concepts of predicability on a hierarchical tree. At the top are terms like 'interesting', 'exists', 'talked about', which are predicable of anything. At the bottom are names, and in between are predicables of some things and not others. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Category') | |
| A reaction: The heirarchy seem be arranged simply by the scope of the predicate. 'Tallest' is predicable of anything in principle, but only of a few things in practice. Is 'John Doe' a name? What is 'cosmic' predicable of? Challenging! |
| 23494 | Conjunctive and disjunctive quantifiers are too specific, and are confined to the finite [Morris,M] |
| Full Idea: There are two problems with defining the quantifiers in terms of conjunction and disjunction. The general statements are unspecific, and do not say which things have the properties, and also they can't range over infinite objects. | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], 5C) | |
| A reaction: That is, the universal quantifier is lots of ands, and the existential is lots of ors. If there only existed finite objects, then naming them all would be universal, and the infinite wouldn't be needed. |
| 23451 | Counting needs to distinguish things, and also needs the concept of a successor in a series [Morris,M] |
| Full Idea: Just distinguishing things is not enough for counting (and hence arithmetic). We need the crucial extra notion of the successor in a series of some kind. | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], Intro.5) | |
| A reaction: This is a step towards the Peano Axioms of arithmetic. The successors could be fingers and toes, taken in a conventional order, and matched one-to-one to the objects. 'My right big toe of cows' means 16 cows (but non-verbally). |
| 23460 | To count, we must distinguish things, and have a series with successors in it [Morris,M] |
| Full Idea: Distinguishing between things is not enough for counting. …We need the crucial extra notion of a successor in a series of a certain kind. | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], Intro) | |
| A reaction: This is the thinking that led to the Dedekind-Peano axioms for arithmetic. E.g. each series member can only have one successor. There is an unformalisable assumption that the series can then be applied to the things. |
| 23452 | Discriminating things for counting implies concepts of identity and distinctness [Morris,M] |
| Full Idea: The discrimination of things for counting needs to bring with it the notion of identity (and, correlatively, distinctness). | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], Intro.5) | |
| A reaction: Morris is exploring how practices like counting might reveal necessary truths about the world. |
| 18900 | Unfortunately for realists, modern logic cannot say that some fact exists [Sommers] |
| Full Idea: Unfortunately for the fate of realist philosophy, modern logic's treatment of 'exists' is resolutely inhospitable to facts as referents of phrases of the form 'the existence or non-existence of φ'. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Realism') | |
| A reaction: Predicate logic has to talk about objects, and then attribute predicates to them. It tends to treat a fact as 'Fa' - this object has this predicate, but that's not really how we understand facts. |
| 13127 | Categories can't overlap; they are either disjoint, or inclusive [Sommers, by Westerhoff] |
| Full Idea: Fred Sommers, in his treatment of types, says that two ontological categories cannot overlap; they are either disjoint, or one properly includes the other. This is sometimes referred to as Sommers' Law. | |
| From: report of Fred Sommers (Types and Ontology [1963], p.355) by Jan Westerhoff - Ontological Categories §24 | |
| A reaction: The 'types', of course, go back to Bertrand Russell's theory of types, which is important in discussions of ontological categories. Carnap pursued it, trying to derive ontological categories from grammatical categories. 85% agree with Sommers. |
| 18898 | In standard logic, names are the only way to refer [Sommers] |
| Full Idea: In modern predicate logic, definite reference by proper names is the primary and sole form of reference. | |
| From: Fred Sommers (Intellectual Autobiography [2005], 'Reference') | |
| A reaction: Hence we have to translate definite descriptions into (logical) names, or else paraphrase them out of existence. The domain only contains 'objects', so only names can uniquely pick them out. |
| 23491 | There must exist a general form of propositions, which are predictabe. It is: such and such is the case [Morris,M] |
| Full Idea: The existence of a general propositional form is proved by the fact that there cannot be a proposition whose form could not have been foreseen (i.e. constructed). The general form of the proposition is: Such and such is the case. | |
| From: Michael Morris (Guidebook to Wittgenstein's Tractatus [2008], 4.5) | |
| A reaction: [last bit in Ogden translation] LW eventually expresses this symbolically. We could just say a proposition is an assertion. This strikes as either a rather empty claim, or an unfounded one. |
| 1513 | The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus] |
| Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born. | |
| From: Herodotus (The Histories [c.435 BCE], 2.123.2) |