22 ideas
2661 | Dialectic is speech cast in the form of logical argument [Cicero] |
Full Idea: Dialectic is speech cast in the form of logical argument. | |
From: M. Tullius Cicero (Academica [c.45 BCE], I.viii.32) |
2673 | There cannot be more than one truth [Cicero] |
Full Idea: There cannot be more than one truth. | |
From: M. Tullius Cicero (Academica [c.45 BCE], II.xlviii.147) |
10794 | The nominalist is tied by standard semantics to first-order, denying higher-order abstracta [Marcus (Barcan)] |
Full Idea: The nominalist finds that standard semantics shackles him to first-order languages if, as nominalists are wont, he is to make do without abstract higher order objects. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.166) | |
A reaction: Aha! Since I am pursuing a generally nominalist strategy in metaphysics, I suddenly see that I must adopt a hostile attitude to higher-order logic! Maybe plural quantification is the way to go, with just first-order objects. |
2669 | Dialectic assumes that all statements are either true or false, but self-referential paradoxes are a big problem [Cicero] |
Full Idea: It is a fundamental principle of dialectic that every statement is either true or false. So is this a true proposition or a false one: "If you say that you are lying and say it truly, you lie"? | |
From: M. Tullius Cicero (Academica [c.45 BCE], II.xxix.95) |
10786 | Anything which refers tends to be called a 'name', even if it isn't a noun [Marcus (Barcan)] |
Full Idea: The tendency has been to call any expression a 'name', however distant from the grammatical category of nouns, provided it is seen as referring. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.162) |
10788 | Nominalists see proper names as a main vehicle of reference [Marcus (Barcan)] |
Full Idea: For a nominalist with an ontology of empirically distinguishable objects, proper names are seen as a primary vehicle of reference. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.162) |
10799 | Nominalists should quantify existentially at first-order, and substitutionally when higher [Marcus (Barcan)] |
Full Idea: For the nominalist, at level zero, where substituends are referring names, the quantifiers may be read existentially. Beyond level zero, the variables and quantifiers are read sustitutionally (though it is unclear whether this program is feasible). | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.167) |
10791 | Substitutional semantics has no domain of objects, but place-markers for substitutions [Marcus (Barcan)] |
Full Idea: On a substitutional semantics of a first-order language, a domain of objects is not specified. Variables do not range over objects. They are place markers for substituends (..and sentences are true-for-all-names, or true-for-at-least-one-name). | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.165) |
10790 | Quantifiers are needed to refer to infinitely many objects [Marcus (Barcan)] |
Full Idea: An adequate language for referring to infinitely many objects would seem to require variables and quantifiers in addition to names. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.164) |
10785 | Maybe a substitutional semantics for quantification lends itself to nominalism [Marcus (Barcan)] |
Full Idea: It has been suggested that a substitutional semantics for quantification theory lends itself to nominalistic aims. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.161) |
10795 | Substitutional language has no ontology, and is just a way of speaking [Marcus (Barcan)] |
Full Idea: Translation into a substitutional language does not force the ontology. It remains, literally, and until the case for reference can be made, a façon de parler. That is the way the nominalist would like to keep it. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.166) |
10798 | A true universal sentence might be substitutionally refuted, by an unnamed denumerable object [Marcus (Barcan)] |
Full Idea: Critics say if there are nondenumerably many objects, then on the substitutional view there might be true universal sentences falsified by an unnamed object, and there must always be some such, for names are denumerable. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.167) | |
A reaction: [See Quine 'Reply to Prof. Marcus' p.183] The problem seems to be that there would be names which are theoretically denumerable, but not nameable, and hence not available for substitution. Marcus rejects this, citing compactness. |
10787 | Is being just referent of the verb 'to be'? [Marcus (Barcan)] |
Full Idea: Being itself has been viewed as referent of the verb 'to be'. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.162) |
10789 | Nominalists say predication is relations between individuals, or deny that it refers [Marcus (Barcan)] |
Full Idea: Nominalists have the major task of explaining how predicates work. They usually construct it as a relation between individuals, or deny the referential function of predicates. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.163) |
10796 | If objects are thoughts, aren't we back to psychologism? [Marcus (Barcan)] |
Full Idea: If objects are thoughts, aren't we back to psychologism? | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.166) | |
A reaction: Personally I don't think that would be the end of the world, but Fregeans go into paroxyms at the mention of 'psychology', because they fear that it destroys objectivity. That may be because they haven't understood thought properly. |
10797 | Substitutivity won't fix identity, because expressions may be substitutable, but not refer at all [Marcus (Barcan)] |
Full Idea: Substitutivity 'salve veritate' cannot define identity since two expressions may be everywhere intersubstitutable and not refer at all. | |
From: Ruth Barcan Marcus (Nominalism and Substitutional Quantifiers [1978], p.167) |
2664 | If we have complete healthy senses, what more could the gods give us? [Cicero] |
Full Idea: If human nature were interrogated by some god as to whether it was content with its own senses in a sound and undamaged state or demanded something better, I cannot see what more it could ask for. | |
From: M. Tullius Cicero (Academica [c.45 BCE], II.vii.19) |
2665 | How can there be a memory of what is false? [Cicero] |
Full Idea: How can there possibly be a memory of what is false? | |
From: M. Tullius Cicero (Academica [c.45 BCE], II.vii.22) |
20800 | Every true presentation can have a false one of the same quality [Cicero] |
Full Idea: [The sceptical Academics say] what is false cannot be perceived, but every true presentation is such that there can be a false presentation of the same quality. | |
From: M. Tullius Cicero (Academica [c.45 BCE], II.40) | |
A reaction: It was the stoics who focused the discussion on 'presentations'. This claim is purely theoretical; no one has ever experienced a false presentation of talking to a family member that was as vivid as the real thing. |
2672 | Virtues must be very detached, to avoid being motivated by pleasure [Cicero] |
Full Idea: None of the virtues can exist unless they are disinterested, for virtue driven to duty by pleasure as a sort of pay is not virtue at all but a deceptive sham and pretence of virtue. | |
From: M. Tullius Cicero (Academica [c.45 BCE], II.xlvi.140) |
1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
Full Idea: Archelaus was the first person to say that the universe is boundless. | |
From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |