9 ideas
| 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) |
| 17402 | Mendeleev saw three principles in nature: matter, force and spirit (where the latter seems to be essence) [Mendeleev, by Scerri] |
| Full Idea: Mendeleev rejected one unifying principles in favour of three basic components of nature: matter (substance), force (energy), and spirit (soul). 'Spirit' is said to be what we now mean by essentialism - what is irreducibly peculiar to the object. | |
| From: report of Dmitri Mendeleev (The Principles of Chemistry [1870]) by Eric R. Scerri - The Periodic Table 04 'Making' |
| 17399 | Elements don't survive in compounds, but the 'substance' of the element does [Mendeleev] |
| Full Idea: Neither mercury as a metal nor oxygen as a gas is contained in mercury oxide; it only contains the substance of the elements, just as steam only contains the substance of ice. | |
| From: Dmitri Mendeleev (The Principles of Chemistry [1870], I:23), quoted by Eric R. Scerri - The Periodic Table 04 'Nature' | |
| A reaction: [1889 edn] Scerri glosses the word 'substance' as meaning essence. |
| 17400 | Mendeleev focused on abstract elements, not simple substances, so he got to their essence [Mendeleev, by Scerri] |
| Full Idea: Because he was attempting to classify abstract elements, not simple substances, Mendeleev was not misled by nonessential chemical properties. | |
| From: report of Dmitri Mendeleev (The Principles of Chemistry [1870]) by Eric R. Scerri - The Periodic Table 04 'Making' | |
| A reaction: I'm not fully clear about this, but I take it that Mendeleev stood back from the messy observations, and tried to see the underlying simpler principles. 'Simple substances' were ones that had not so far been decomposed. |
| 17401 | Mendeleev had a view of elements which allowed him to overlook some conflicting observations [Mendeleev] |
| Full Idea: His view of elements allowed Mendeleev to maintain the validity of the periodic table even in instances where observational evidence seemed to point against it. | |
| From: Dmitri Mendeleev (The Principles of Chemistry [1870]), quoted by Eric R. Scerri - The Periodic Table 04 'Making' | |
| A reaction: Mendeleev seems to have focused on abstract essences of elements, rather than on the simplest substances they had so far managed to isolate. |
| 3804 | Darwin's idea was the best idea ever [Dennett] |
| Full Idea: If I were to give an award for the single best idea anyone has ever had, I'd give it to Darwin. | |
| From: Daniel C. Dennett (Darwin's Dangerous Idea [1995], §1.1) |