6 ideas
| 13827 | Logical consequence isn't a black box (Tarski's approach); we should explain how arguments work [Prawitz] |
| Full Idea: Defining logical consequence in the way Tarski does is a rather meagre result, treating an argument as a black box, observing input and output, while disregarding inner structure. We should define logical consequence on the basis of valid arguments. | |
| From: Dag Prawitz (On the General Idea of Proof Theory [1974], §2) |
| 13826 | Model theory looks at valid sentences and consequence, but not how we know these things [Prawitz] |
| Full Idea: In model theory, which has dominated the last decades, one concentrates on logically valid sentences, and what follows logically from what, but one disregards questions concerning how we know these things. | |
| From: Dag Prawitz (On the General Idea of Proof Theory [1974], §1) |
| 1748 | Archelaus was the first person to say that the universe is boundless [Archelaus, by Diog. Laertius] |
| Full Idea: Archelaus was the first person to say that the universe is boundless. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 02.Ar.3 |
| 5989 | Archelaus said life began in a primeval slime [Archelaus, by Schofield] |
| Full Idea: Archelaus wrote that life on Earth began in a primeval slime. | |
| From: report of Archelaus (fragments/reports [c.450 BCE]) by Malcolm Schofield - Archelaus | |
| A reaction: This sounds like a fairly clearcut assertion of the production of life by evolution. Darwin's contribution was to propose the mechanism for achieving it. We should honour the name of Archelaus for this idea. |
| 21798 | To universalise 'give everything to the poor' leads to absurdity [Hegel] |
| Full Idea: If everyone gave everything to the poor, then soon there would be no more poor to give anything to, or no more persons who would have anything to give. | |
| From: Georg W.F.Hegel (Lectures on the Philosophy of Religion [1827], III: 152), quoted by Stephen Houlgate - An Introduction to Hegel 10 'Faith' | |
| A reaction: Matthew 5:8, 19:21. Beautifully clear. [I always believed that I had thought of this idea - but not so]. If the logic is that it is better to be poor than to be rich, then the implication is that all excess wealth should be thrown into the sea. |
| 21797 | Immortality does not come at a later time, but when pure knowing Spirit fully grasps the universal [Hegel] |
| Full Idea: The immortality of the soul must not be imagined as though it first emerges into actuality at some later time; rather it is a present quality. ...As pure knowing or as thinking, Spirit has the universal for its object - this is eternity. | |
| From: Georg W.F.Hegel (Lectures on the Philosophy of Religion [1827], III: 208), quoted by Stephen Houlgate - An Introduction to Hegel 10 'Death' | |
| A reaction: An unusual view of immortality, which challenges orthodoxy. The idea seems to be that 'pure knowing' is a grasping of the pure reason which embodies nature, which in turn is the nature of God. You enter eternity, rather than reside in it? |