9 ideas
| 16186 | The Barcan Formulas express how to combine modal operators with classical quantifiers [Simchen] |
| Full Idea: The Barcan Formula and its converse gives expression to the most straightforward way of combining modal operators with classical quantification. | |
| From: Ori Simchen (The Barcan Formula and Metaphysics [2013], §1) |
| 16187 | The Barcan Formulas are orthodox, but clash with the attractive Actualist view [Simchen] |
| Full Idea: The Barcan Formulas are a threat to 'actualism' in modal metaphysics, which seems regrettable since the Formulas are validated by standard modal logics, but clash with the plausible and attractive actualist view (that there are no merely possible things). | |
| From: Ori Simchen (The Barcan Formula and Metaphysics [2013], §1) | |
| A reaction: He notes that the Barcan Formulas 'appear to require quantification over possibilia'. So are you prepared to accept the 'possible elephant in your kitchen'? Conceptually yes, but actually no, I would have thought. So possibilia are conceptual. |
| 16190 | BF implies that if W possibly had a child, then something is possibly W's child [Simchen] |
| Full Idea: In accordance with the Barcan Formula we assume that if it is possible that Wittgenstein should have had a child, then something or other is possibly Wittgentein's child. | |
| From: Ori Simchen (The Barcan Formula and Metaphysics [2013], §5) | |
| A reaction: Put like this it sounds unpersuasive. What is the something or other? Someone else's child? A dustbin? A bare particular? Wittgenstein's child? If it was the last one, how could it be Wittgenstein's child while only possibly being that thing? |
| 10580 | Mathematics is both necessary and a priori because it really consists of logical truths [Yablo] |
| Full Idea: Mathematics seems necessary because the real contents of mathematical statements are logical truths, which are necessary, and it seems a priori because logical truths really are a priori. | |
| From: Stephen Yablo (Abstract Objects: a Case Study [2002], 10) | |
| A reaction: Yablo says his logicism has a Kantian strain, because numbers and sets 'inscribed on our spectacles', but he takes a different view (in the present Idea) from Kant about where the necessity resides. Personally I am tempted by an a posteriori necessity. |
| 10579 | Putting numbers in quantifiable position (rather than many quantifiers) makes expression easier [Yablo] |
| Full Idea: Saying 'the number of Fs is 5', instead of using five quantifiers, puts the numeral in quantifiable position, which brings expressive advantages. 'There are more sheep in the field than cows' is an infinite disjunction, expressible in finite compass. | |
| From: Stephen Yablo (Abstract Objects: a Case Study [2002], 08) | |
| A reaction: See Hofweber with similar thoughts. This idea I take to be a key one in explaining many metaphysical confusions. The human mind just has a strong tendency to objectify properties, relations, qualities, categories etc. - for expression and for reasoning. |
| 10577 | Concrete objects have few essential properties, but properties of abstractions are mostly essential [Yablo] |
| Full Idea: Objects like me have a few essential properties, and numerous accidental ones. Abstract objects are a different story. The intrinsic properties of the empty set are mostly essential. The relations of numbers are also mostly essential. | |
| From: Stephen Yablo (Abstract Objects: a Case Study [2002], 01) |
| 10578 | We are thought to know concreta a posteriori, and many abstracta a priori [Yablo] |
| Full Idea: Our knowledge of concreta is a posteriori, but our knowledge of numbers, at least, has often been considered a priori. | |
| From: Stephen Yablo (Abstract Objects: a Case Study [2002], 02) |
| 16188 | Serious Actualism says there are no facts at all about something which doesn't exist [Simchen] |
| Full Idea: Serious Actualism is the view that in possible circumstances in which something does not exist there are no facts about it of any kind, including its very non-existence | |
| From: Ori Simchen (The Barcan Formula and Metaphysics [2013], §1 n4) | |
| A reaction: He suggests that the Converse Barcan Formula implies this view. It sounds comparable to the view of Presentism about time, that no future or past truthmakers exist right now. If a new square table were to exist, it would have four corners. |
| 6040 | There is no universal goal to human life [Aenesidemus, by Photius] |
| Full Idea: Aenesidemus does not allow either happiness or pleasure or prudence or any other goal held by anyone on the basis of philosophical doctrine as the goal of life; rather, he says that there just is no such thing as a goal which is recognised by all people. | |
| From: report of Aenesidemus (Pyrrhonian Arguments (frags) [c.60 BCE], Bk 8) by 'Photius Bibliotheca' - Aenesidimus (frags) 170b | |
| A reaction: This is probably the dominant modern (post-Darwinian, existentialist) view. Personally I am sympathetic to the Aristotelian view that (to some extent) appropriate goals for life can be inferred from a fairly stable human nature. |