6 ideas
| 5035 | The two basics of reasoning are contradiction and sufficient reason [Leibniz] |
| Full Idea: The two first principles of reasoning are: the principle of contradiction, and the principle of the need for giving a reason. | |
| From: Gottfried Leibniz (A Specimen of Discoveries [1686], p.75) | |
| A reaction: Could animals have any reasoning ability (say, in solving a physical problem)? Leibniz's criteria both require language. Note the overlapping of the principle of sufficient reason (there IS a reason) with the contractual idea of GIVING reasons. |
| 5987 | Alcmaeon was the first to say the brain is central to thinking [Alcmaeon, by Staden, von] |
| Full Idea: Alcmaeon apparently was the first Greek to assign central cognitive and biological functions to the brain. | |
| From: report of Alcmaeon (fragments/reports [c.490 BCE]) by Heinrich von Staden - Alcmaeon | |
| A reaction: The name of Alcmaeon should be remembered with honour. This was 200 years before Aristotle, who still hadn't worked it out. I presume Alcmaeon inferred the truth from head injuries, which is overwhelming evidence, if you notice it. |
| 5038 | Assume that mind and body follow their own laws, but God has harmonised them [Leibniz] |
| Full Idea: Why not assume that God initially created the soul and body with so much ingenuity that, whilst each follows its own laws and properties and operations, all thing agree most beautifull among themselves? This is the 'hypothesis of concomitance'. | |
| From: Gottfried Leibniz (A Specimen of Discoveries [1686], p.80) | |
| A reaction: They may be in beautifully planned harmony, but how do we know that they are in harmony? Presumably their actions must be compared, and God would even have to harmonise the comparison. Parallelism seems to imply epiphenomenalism or idealism. |
| 16383 | Puzzled Pierre has two mental files about the same object [Recanati on Kripke] |
| Full Idea: In Kripke's puzzle about belief, the subject has two distinct mental files about one and the same object. | |
| From: comment on Saul A. Kripke (A Puzzle about Belief [1979]) by François Recanati - Mental Files 17.1 | |
| A reaction: [Pierre distinguishes 'London' from 'Londres'] The Kripkean puzzle is presented as very deep, but I have always felt there was a simple explanation, and I suspect that this is it (though I will leave the reader to think it through, as I'm very busy…). |
| 24043 | Soul must be immortal, since it continually moves, like the heavens [Alcmaeon, by Aristotle] |
| Full Idea: Alcmaeon says that the soul is immortal because it resembles immortal things and that this affection belongs to it because it is always in movement, like divine things, such the moon, the sun, the stars and the whole heaven. | |
| From: report of Alcmaeon (fragments/reports [c.490 BCE], DK 24) by Aristotle - De Anima 405a30 | |
| A reaction: Hm. Fish and rivers seem to be continually moving too. Presumably we are like gods, but then Greek gods seem awfully like humans. I don't know the history of belief in immortality; an interesting topic. |
| 5037 | God doesn't decide that Adam will sin, but that sinful Adam's existence is to be preferred [Leibniz] |
| Full Idea: God does not decide whether Adam should sin, but whether that series of things in which there is an Adam whose perfect individual notion involves sin should nevertheless be preferred to others. | |
| From: Gottfried Leibniz (A Specimen of Discoveries [1686], p.78) | |
| A reaction: Compare whether the person responsible for setting a road speed limit is responsible for subsequent accidents. Leibniz's belief that the world could have been made no better than it is (by an omnipotent being) strikes me as blind faith, not an argument. |