14 ideas
| 13338 | '"It is snowing" is true if and only if it is snowing' is a partial definition of the concept of truth [Tarski] |
| Full Idea: Statements of the form '"it is snowing" is true if and only if it is snowing' and '"the world war will begin in 1963" is true if and only if the world war will being in 1963' can be regarded as partial definitions of the concept of truth. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.404) | |
| A reaction: The key word here is 'partial'. Truth is defined, presumably, when every such translation from the object language has been articulated, which is presumably impossible, given the infinity of concatenated phrases possible in a sentence. |
| 13337 | A language: primitive terms, then definition rules, then sentences, then axioms, and finally inference rules [Tarski] |
| Full Idea: For a language, we must enumerate the primitive terms, and the rules of definition for new terms. Then we must distinguish the sentences, and separate out the axioms from amng them, and finally add rules of inference. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.402) | |
| A reaction: [compressed] This lays down the standard modern procedure for defining a logical language. Once all of this is in place, we then add a semantics and we are in business. Natural deduction tries to do without the axioms. |
| 14235 | Saying 'they can become a set' is a tautology, because reference to 'they' implies a collection [Cargile] |
| Full Idea: If the rule is asserted 'Given any well-determined objects, they can be collected into a set by an application of the 'set of' operation', then on the usual account of 'they' this is a tautology. Collection comes automatically with this form of reference. | |
| From: James Cargile (Paradoxes: Form and Predication [1979], p.115), quoted by Oliver,A/Smiley,T - What are Sets and What are they For? Intro | |
| A reaction: Is this a problem? Given they are well-determined (presumably implying countable) there just is a set of them. That's what set theory is, I thought. Of course, the iterative view talks of 'constructing' the sets, but the construction looks unstoppable. |
| 13335 | Semantics is the concepts of connections of language to reality, such as denotation, definition and truth [Tarski] |
| Full Idea: Semantics is the totality of considerations concerning concepts which express connections between expressions of a language and objects and states of affairs referred to by these expressions. Examples are denotation, satisfaction, definition and truth. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.401) | |
| A reaction: Interestingly, he notes that it 'is not commonly recognised' that truth is part of semantics. Nowadays truth seems to be the central concept in most semantics. |
| 13336 | A language containing its own semantics is inconsistent - but we can use a second language [Tarski] |
| Full Idea: People have not been aware that the language about which we speak need by no means coincide with the language in which we speak. ..But the language which contains its own semantics must inevitably be inconsistent. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.402) | |
| A reaction: It seems that Tarski was driven to propose the metalanguage approach mainly by the Liar Paradox. |
| 13339 | A sentence is satisfied when we can assert the sentence when the variables are assigned [Tarski] |
| Full Idea: Here is a partial definition of the concept of satisfaction: John and Peter satisfy the sentential function 'X and Y are brothers' if and only if John and Peter are brothers. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.405) | |
| A reaction: Satisfaction applies to open sentences and truth to closed sentences (with named objects). He uses the notion of total satisfaction to define truth. The example is a partial definition, not just an illustration. |
| 13340 | Satisfaction is the easiest semantical concept to define, and the others will reduce to it [Tarski] |
| Full Idea: It has been found useful in defining semantical concepts to deal first with the concept of satisfaction; both because the definition of this concept presents relatively few difficulties, and because the other semantical concepts are easily reduced to it. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.406) | |
| A reaction: See Idea 13339 for his explanation of satisfaction. We just say that a open sentence is 'acceptable' or 'assertible' (or even 'true') when particular values are assigned to the variables. Then sentence is then 'satisfied'. |
| 13341 | Using the definition of truth, we can prove theories consistent within sound logics [Tarski] |
| Full Idea: Using the definition of truth we are in a position to carry out the proof of consistency for deductive theories in which only (materially) true sentences are (formally) provable. | |
| From: Alfred Tarski (The Establishment of Scientific Semantics [1936], p.407) | |
| A reaction: This is evidently what Tarski saw as the most important first fruit of his new semantic theory of truth. |
| 4045 | Children may have three innate principles which enable them to learn to count [Goldman] |
| Full Idea: It has been proposed (on the basis of observations) that young children have three innate principles of counting - one-to-one correspondence of number to item, stable order for numbers, and cardinality (which labels the nth item counted). | |
| From: Alvin I. Goldman (Phil Applications of Cognitive Science [1993], p.60) | |
| A reaction: I like the idea of observed patterns as central (which is the one-to-one principle). But the other two principles are plausible, and show why pure empiricism won't work. |
| 4044 | Rat behaviour reveals a considerable ability to count [Goldman] |
| Full Idea: Rats can determine the number of times they have pressed a lever up to at least twenty-four presses,…and can consistently turn down the fifth tunnel on the left in a maze. | |
| From: Alvin I. Goldman (Phil Applications of Cognitive Science [1993], p.58) | |
| A reaction: This seems to encourage an empirical view of maths (pattern recognition?) rather than a Platonic one. Or numbers are innate in rat brains? |
| 4048 | Infant brains appear to have inbuilt ontological categories [Goldman] |
| Full Idea: Infant behaviour implies inbuilt ontological categories of thing, place, event, path, action, sound, manner, amount and number. ...There is an algebra of relationships between them. | |
| From: Alvin I. Goldman (Phil Applications of Cognitive Science [1993], p.109) | |
| A reaction: Interesting. We would expect the categories in infant brains to have instrumental value, but we don't have to accept them as true. Adults (even Aristotle) are big infants. |
| 4043 | Elephants can be correctly identified from as few as three primitive shapes [Goldman] |
| Full Idea: An elephant may be fully represented by nine primitive shapes ('geons'), but it may require as few as three geons in appropriate relations to be correctly identified. | |
| From: Alvin I. Goldman (Phil Applications of Cognitive Science [1993], p.7) | |
| A reaction: Encouraging the idea of the mind as a maker of maps and models |
| 4049 | The way in which colour experiences are evoked is physically odd and unpredictable [Goldman] |
| Full Idea: A unique yellow experience may be evoked with monochrome light of 580nm, or a mixture of 540nm and 670nm. ..Our interpretation of colour experience is a highly idiosyncratic artefact of our visual system. | |
| From: Alvin I. Goldman (Phil Applications of Cognitive Science [1993], p.117) | |
| A reaction: This confirms what I have always thought - that colour (as qualia) is strictly a feature of minds, not of the world. |
| 4047 | Gestalt psychology proposes inbuilt proximity, similarity, smoothness and closure principles [Goldman] |
| Full Idea: Gestalt psychology claims that there are at least four unlearned factors in perceptual grouping - the principles of proximity (close things), of similarity, of good continuation (extending lines in a smooth course), and closure (which completes figures). | |
| From: Alvin I. Goldman (Phil Applications of Cognitive Science [1993], p.103) | |
| A reaction: This offers a bridge between Hume's associationism and rationalist claims of innate ideas |