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. |
| 17962 | The truth-maker principle is that every truth has a sufficient truth-maker [Forrest] |
| Full Idea: Item x is said to be a sufficient truth-maker for truth-bearer p just in case necessarily if x exists then p is true. ...Every truth has a sufficient truth-maker. Hence, I take it, the sum of all sufficient truth-makers is a universal truth-maker. | |
| From: Peter Forrest (General Facts,Phys Necessity, and Metaph of Time [2006], 1) | |
| A reaction: Note that it is not 'necessary', because something else might make p true instead. |
| 2572 | Logical truth seems much less likely to 'correspond to the facts' than factual truth does [Haack] |
| Full Idea: It is surely less plausible to suppose that logical truth consists in correspondence to the facts than that 'factual' truth does. | |
| From: Susan Haack (Philosophy of Logics [1978], 7.6) |
| 2570 | The same sentence could be true in one language and meaningless in another, so truth is language-relative [Haack] |
| Full Idea: The definition of truth will have to be, Tarski argues, relative to a language, for one and the same sentence may be true in one language, and false or meaningless in another. | |
| From: Susan Haack (Philosophy of Logics [1978], 7.5) |
| 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. |
| 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. |