13 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. |
| 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. |
| 20525 | Free markets lead to boom and bust, pointless middlemen, and alienated workers [Engels] |
| Full Idea: Free markets inevitably lead to unemployment and ruined businesses, when the capitalist market is punctuated by a 'trade cycle' of boom and bust. .. There are speculating, swindling middlemen. ...and the nature of work is degrading and alienated. | |
| From: Friedrich Engels (Speeches in Elberfeld [1849]), quoted by Jonathan Wolff - An Introduction to Political Philosophy (Rev) 5 'Arguments' | |
| A reaction: [compression of Wolff's summary] Wolff observes that middlemen are heroes to lovers of the market. The idea of alienation seems to be that everyone should be in charge of their own work. That may approach anarchy. |
| 23061 | Free atheism should start by questioning its faith in humanity [Gray] |
| Full Idea: A free-thinking atheism would begin by questioning the prevailing faith in humanity. But there is little prospect of contemporary atheists giving up their reverence for this phantom. | |
| From: John Gray (Seven Types of Atheism [2018], Conc) | |
| A reaction: He seems to be referring to 'humanism', which I take to be quite different from atheism. I take it as obvious that simple atheism is entirely neutral on the question of whether we should have 'faith' in humanity (which presumably mean optimism). |
| 23057 | Gnosticism has a supreme creator God, giving way to a possibly hostile Demiurge [Gray] |
| Full Idea: Gnostic traditions envisage a supreme God that created the universe and then withdrew into itself, leaving the world to be ruled by a lesser god, or Demiurge, which might be indifferent or hostile to mankind. | |
| From: John Gray (Seven Types of Atheism [2018], Intro) | |
| A reaction: It doesn't seem to solve any problems, given that the first God is 'supreme', and is therefore responsible for the introduction and actions of the later Demiurge. |
| 23056 | Judaism only became monotheistic around 550 BCE [Gray] |
| Full Idea: It was only sometime around the sixth century BC, during the period when the Israelites returned to Jerusalem, that the idea that there is only one God emerged in Jewish religion. | |
| From: John Gray (Seven Types of Atheism [2018], Intro) | |
| A reaction: There seems to be a parallel move among the Greeks to elevate Zeus to special status. |
| 23055 | Christians introduced the idea that a religion needs a creed [Gray] |
| Full Idea: The notion that religions are creeds - lists of propositions or doctrines that everyone must accept or reject - emerged only with Christianity. | |
| From: John Gray (Seven Types of Atheism [2018], Intro) | |
| A reaction: With a creed comes the possibility of heresy. I''m not happy with children being taught to recite something which begins 'I believe…', but which they have never thought about and barely understand. |
| 23058 | Buddhism has no divinity or souls, and the aim is to lose the illusion of a self [Gray] |
| Full Idea: Buddhism says nothing of any divine mind and rejects any idea of the soul. The world consists of processes and events. The human sense of self is an illusion; freedom is found in ridding oneself of this illusion. | |
| From: John Gray (Seven Types of Atheism [2018], Intro) | |
| A reaction: I'm not clear why shaking off the illusion of a self is a superior state. Freedom to do what? Presumably nothing at all, since there is no self to desire anything. |