6 ideas
| 8000 | He who is ignorant of the history of philosophy is doomed to repeat it [Santayana, by MacIntyre] |
| Full Idea: Santayana remarked that he who is ignorant of the history of philosophy is doomed to repeat it. | |
| From: report of George Santayana (The Life of Reason [1906]) by Alasdair MacIntyre - A Short History of Ethics Ch.1 | |
| A reaction: Santayana's remark seems to have been about history in general, so this is a Macintyre thought. It obviously has a lot of truth, and most great philosophers seem hugely knowledgeable. However, ignorance brings a kind of freedom. |
| 9390 | Logic guides thinking, but it isn't a substitute for it [Rumfitt] |
| Full Idea: Logic is part of a normative theory of thinking, not a substitute for thinking. | |
| From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.13) | |
| A reaction: There is some sort of logicians' dream, going back to Leibniz, of a reasoning engine, which accepts propositions and outputs inferences. I agree with this idea. People who excel at logic are often, it seems to me, modest at philosophy. |
| 9389 | Vague membership of sets is possible if the set is defined by its concept, not its members [Rumfitt] |
| Full Idea: Vagueness in respect of membership is consistency with determinacy of the set's identity, so long as a set's identity is taken to consist, not in its having such-and-such members, but in its being the extension of a concept. | |
| From: Ian Rumfitt (The Logic of Boundaryless Concepts [2007], p.5) | |
| A reaction: I find this view of sets much more appealing than the one that identifies a set with its members. The empty set is less of a problem, as well as non-existents. Logicians prefer the extensional view because it is tidy. |
| 7598 | Zoroaster and the Hebrew prophets evolved different versions of monotheism [Zoroaster, by Armstrong,K] |
| Full Idea: Zoroaster and the Hebrew prophets evolved different versions of monotheism. | |
| From: report of Zoroaster (The Gathas (seventeen hymns) [c.900 BCE]) by Karen Armstrong - A History of God Ch.1 | |
| A reaction: This seems to be the consensus on the origins of monotheism, which places the development much earlier than the appearance of the idea in Greek philosophy. |
| 7472 | Zarathustra was the first to present a god who is an abstract concept [Zoroaster] |
| Full Idea: Zarathustra's achievement was for the first time to present a god who is an abstract concept - he broke with the tradition of a pantheon of gods. | |
| From: Zoroaster (The Gathas (seventeen hymns) [c.900 BCE]), quoted by Peter Watson - Ideas Ch.05 | |
| A reaction: The more abstract the gods become, the harder it is to challenge their existence. |
| 20672 | Zoroastrianism saw the world as a battle between good evil gods [Zoroaster, by Harari] |
| Full Idea: Zoroastrianism saw the world as a cosmic battle between the good god Ahura Mazda and the evil god Angra Mainyu. | |
| From: report of Zoroaster (The Gathas (seventeen hymns) [c.900 BCE]) by Yuval Noah Harari - Sapiens: brief history of humankind 12 'Battle' | |
| A reaction: Hm. This contradicts the impression I had gained that it was monotheist. |