Combining Texts

All the ideas for 'fragments/reports', 'works' and 'Commentary on Euclid's 'Elements''

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6 ideas

14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
Geometrical proofs do not show causes, as when we prove a triangle contains two right angles [Proclus]
     Full Idea: Geometry does not ask 'why?' ..When from the exterior angle equalling two opposite interior angles it is shown that the interior angles make two right angles, this is not a causal demonstration. With no exterior angle they still equal two right angles.
     From: Proclus (Commentary on Euclid's 'Elements' [c.452], p.161-2), quoted by Paolo Mancosu - Explanation in Mathematics §5
     A reaction: A very nice example. It is hard to imagine how one might demonstrate the cause of the angles making two right angles. If you walk, turn left x°, then turn left y°, then turn left z°, and x+y+z=180°, you end up going in the original direction.
18. Thought / E. Abstraction / 1. Abstract Thought
The origin of geometry started in sensation, then moved to calculation, and then to reason [Proclus]
     Full Idea: It is unsurprising that geometry was discovered in the necessity of Nile land measurement, since everything in the world of generation goes from imperfection to perfection. They would naturally pass from sense-perception to calculation, and so to reason.
     From: Proclus (Commentary on Euclid's 'Elements' [c.452]), quoted by Charles Chihara - A Structural Account of Mathematics 9.12 n55
     A reaction: The last sentence is the core of my view on abstraction, that it proceeds by moving through levels of abstraction, approaching more and more general truths.
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / a. Preconditions for ethics
Levinas took 'first philosophy' to begin with seeing the vulnerable faces of others [Levinas, by Aho]
     Full Idea: Levinas forwarded a notion of 'ethics as first philosophy' that begins from the concete exposure and openness to 'the face' of the other, an experience of vulnerability and suffering that undercuts our ordinary egoistic and objectifying tendencies.
     From: report of Emmanuel Levinas (works [1956]) by Kevin Aho - Existentialism: an introduction 1 'Existentialism'
     A reaction: Iris Murdoch speaks of seeing a falcon in flight as having a similar effect of diminishing the ego. If the main focus is on potential 'suffering' does this eventually cash out as utilitarianism? I bet not!
24. Political Theory / D. Ideologies / 9. Communism
Levinas says Marxism is the replacement of individualist ethics, by solidarity and sociality [Levinas, by Critchley]
     Full Idea: For Levinas, Marxism is the absorption of the ethical in the socioeconomic, and so it is the disappearance of the face-to-face relation and the privileging of relations of solidarity and anonymous sociality, which he calls 'socialism'.
     From: report of Emmanuel Levinas (works [1956]) by Simon Critchley - Impossible Objects: interviews 1
     A reaction: Startling, if you are not used to this sort of thing. If you are in trouble, I should help you, not because you are you, or a human being, but because you are a member of my group? So what about the Good Samaritan? Or solidarity with humanity? Animals?
25. Social Practice / E. Policies / 5. Education / b. Education principles
Learned men gain more in one day than others do in a lifetime [Posidonius]
     Full Idea: In a single day there lies open to men of learning more than there ever does to the unenlightened in the longest of lifetimes.
     From: Posidonius (fragments/reports [c.95 BCE]), quoted by Seneca the Younger - Letters from a Stoic 078
     A reaction: These remarks endorsing the infinite superiority of the educated to the uneducated seem to have been popular in late antiquity. It tends to be the religions which discourage great learning, especially in their emphasis on a single book.
27. Natural Reality / D. Time / 1. Nature of Time / d. Time as measure
Time is an interval of motion, or the measure of speed [Posidonius, by Stobaeus]
     Full Idea: Posidonius defined time thus: it is an interval of motion, or the measure of speed and slowness.
     From: report of Posidonius (fragments/reports [c.95 BCE]) by John Stobaeus - Anthology 1.08.42
     A reaction: Hm. Can we define motion or speed without alluding to time? Looks like we have to define them as a conjoined pair, which means we cannot fully understand either of them.