Combining Texts

All the ideas for 'works', 'Building Blocks of Mathematical Logic' and 'Intuitionism'

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6 ideas

5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
Variables are auxiliary notions, and not part of the 'eternal' essence of logic [Schönfinkel]
     Full Idea: A variable in a proposition of logic ....has the status of a mere auxiliary notion that is really inappropriate to the constant, 'eternal' essence of the propositions of logic.
     From: Moses Schönfinkel (Building Blocks of Mathematical Logic [1924], §1)
     A reaction: He presumably thinks that what the variables stand for (and he mentions 'argument places' and 'operators') will be included in the essence. My attention was caught by the thought that he takes logic to have an essence.
6. Mathematics / B. Foundations for Mathematics / 3. Axioms for Geometry
Archimedes defined a straight line as the shortest distance between two points [Archimedes, by Leibniz]
     Full Idea: Archimedes gave a sort of definition of 'straight line' when he said it is the shortest line between two points.
     From: report of Archimedes (fragments/reports [c.240 BCE]) by Gottfried Leibniz - New Essays on Human Understanding 4.13
     A reaction: Commentators observe that this reduces the purity of the original Euclidean axioms, because it involves distance and measurement, which are absent from the purest geometry.
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
If there are intuited moral facts, why should we care about them? [Dancy,J]
     Full Idea: Critics asked (of intuitionism) why, if moral facts are as the intuitionists say, we should care about them at all.
     From: Jonathan Dancy (Intuitionism [1991])
     A reaction: It is a good question, as we don't care much about other a priori truths, such as the square root of 169.
Internalists say that moral intuitions are motivating; externalist say a desire is also needed [Dancy,J]
     Full Idea: There is an internalist view of intuitionism, saying that to accept that one's action is wrong is itself to be motivated not to do it. Externalists (like Ross) say that moral judgements need the help of an independent desire to motivate us.
     From: Jonathan Dancy (Intuitionism [1991])
     A reaction: The internalists would be closer to Kant or Plato (for whom reason or pure ideas motivate), while externalist would favour Hume's belief/desire account of human actions. I like Kant and Plato, but Hume is more plausible. Dancy disagrees (Idea 7262).
Obviously judging an action as wrong gives us a reason not to do it [Dancy,J]
     Full Idea: It is ludicrous to say that we might accept an action is outrageously wrong and still think of this as not in itself giving us good reason to hold back.
     From: Jonathan Dancy (Intuitionism [1991])
     A reaction: If we think of some dreadful man-made famine in a remote continent, our judgement may well give a reason to act, but apathy usually intervenes. We are discussing a purely theoretical motive on the one hand, and an actual motivator on the other.
Moral facts are not perceived facts, but perceived reasons for judgements [Dancy,J]
     Full Idea: I intend to suggest that moral facts are best thought of not as facts perceived but as reasons recognised in the exercise of practical moral judgement.
     From: Jonathan Dancy (Intuitionism [1991])
     A reaction: I'm not convinced by this modified version. Why should the fact that someone is in pain be, in itself, a reason to prevent it? There are different cultural traditions for response to the pain of others. We are the squeamish tradition.