display all the ideas for this combination of philosophers
24 ideas
13009 | A reason is a known truth which leads to assent to some further truth [Leibniz] |
Full Idea: A reason is a known truth whose connection with some less well-known truth leads us to give our assent to the latter. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 4.17) | |
A reaction: This is plainly false, because you can have a reason for believing something, but still not give your assent to it, presumably because of counter-reasons. And a false belief could also be a reason, even to believe a truth. Tut tut. |
16897 | Reason is the faculty for grasping apriori necessary truths [Leibniz, by Burge] |
Full Idea: Leibniz actually characterises reason as the faculty for apprehending priori, necessary truths. | |
From: report of Gottfried Leibniz (works [1690]) by Tyler Burge - Frege on Apriority (with ps) 2 | |
A reaction: No wonder it is called the Age of Reason when the claims are this grandiose. |
19335 | Reasonings have a natural ordering in God's understanding, but only a temporal order in ours [Leibniz] |
Full Idea: All reasonings are eminent in God, and they preserve an order among themselves in his understanding as well as in ours; but for him this is just an order and a priority of nature, whereas for us there is a priority of time. | |
From: Gottfried Leibniz (The Theodicy [1710], p.192), quoted by Franklin Perkins - Leibniz: Guide for the Perplexed 2.III | |
A reaction: This view is found in Frege, and seems to be the hallmark of rationalist philosophy. There is an apriori assumption that reality has a rational order, so that pure reason is a tool for grasping it. Lewis's 'mosaic' of experiences has no order. |
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. |
3346 | For Leibniz rationality is based on non-contradiction and the principle of sufficient reason [Leibniz, by Benardete,JA] |
Full Idea: Leibniz distinguished two fundamental principles of rationality - the principle of non-contradiction and the principle of sufficient reason. | |
From: report of Gottfried Leibniz (works [1690]) by José A. Benardete - Metaphysics: the logical approach Ch.18 |
12963 | Opposing reason is opposing truth, since reason is a chain of truths [Leibniz] |
Full Idea: To speak against reason is to speak against truth, for reason is a chain of truths. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.21) | |
A reaction: Truth has a talismanic quality here (which it didn't always have). This is a lovely slogan for defenders of the Enlightenment. It forces modern critics of the Enlightenment (Adorno etc) to launch an attack on truth, which is a doomed line. |
19433 | The universe is infinitely varied, so the Buridan's Ass dilemma could never happen [Leibniz] |
Full Idea: The Buridan's Ass case of perfect equilibrium is chimerical. ...The universe has no centre and its parts are infinitely varied; thus it will never happen that all will be perfectly equal and will strike equally from one side or the other. | |
From: Gottfried Leibniz (Letters to Coste [1707], 1707) | |
A reaction: Can the great Leibniz have missed the point? Surely all that matters is that the ass cannot distinguish the two options - not that they actually are identical in every detail? If the ass is short-sighted, that should be easy to set up. |
19404 | Necessities rest on contradiction, and contingencies on sufficient reason [Leibniz] |
Full Idea: The principle of contradiction is the principle of necessity, and the principle that a sufficient reason must be given is the principle of contingency. | |
From: Gottfried Leibniz (On Sufficient Reason [1686], p.95) | |
A reaction: [this paragraph is actually undated] Contradictions occur in concrete actuality, as well as in theories and formal systems. If so, then there are necessities in nature. Are they discoverable a posteriori? Leibniz says not. |
19360 | General principles, even if unconscious, are indispensable for thinking [Leibniz] |
Full Idea: General principles enter into our thoughts, serving as their inner core and their mortar. Even if we give no thought to them, they are necessary for thought, as muscles and tendons are for walking. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 1.01.20) | |
A reaction: Famously, Leibniz identified sufficient reason and non-contradiction as the two foundational principles. Modern logicians seem less keen on this idea, but then they have less interest in how we actually think. |
5042 | For every event it is possible for an omniscient being to give a reason for its occurrence [Leibniz] |
Full Idea: Nothing ever takes place without its being possible for one who knew everything to give some reason why it should have happened rather than not. | |
From: Gottfried Leibniz (Letter on Freedom [1689], p.112) | |
A reaction: Presumably there will be GOOD reason why genocide occurs. Note that there is a reason for every 'event'. Is there a reason for every truth? Presumably not, or there would have to be reasons for self-evident truths. |
3347 | Leibniz said the principle of sufficient reason is synthetic a priori, since its denial is not illogical [Leibniz, by Benardete,JA] |
Full Idea: Leibniz assigns synthetic a priori status to the principle of sufficient reason, readily conceding that one can deny it without fear of inconsistency. | |
From: report of Gottfried Leibniz (works [1690]) by José A. Benardete - Metaphysics: the logical approach Ch.18 |
2098 | The principle of sufficient reason is needed if we are to proceed from maths to physics [Leibniz] |
Full Idea: In order to proceed from mathematics to physics the principle of sufficient reason is necessary, that nothing happens without there being a reason why it should be thus rather than otherwise. | |
From: Gottfried Leibniz (Letters to Samuel Clarke [1716], §2) |
4642 | No fact can be real and no proposition true unless there is a Sufficient Reason (even if we can't know it) [Leibniz] |
Full Idea: The principle of sufficient reason says no fact can be real or existing and no proposition can be true unless there is a sufficient reason why it should be thus and not otherwise, even though in most cases these reasons cannot be known to us. | |
From: Gottfried Leibniz (Monadology [1716], §32) | |
A reaction: I think of this as my earliest philosophical perception, a childish rebellion against being told that there was 'no reason' for something. My intuition tells me that it is correct, and the foundation of ontology and truth. Don't ask me to justify it! |
3646 | There is always a reason why things are thus rather than otherwise [Leibniz] |
Full Idea: Nothing happens without a sufficient reason why it should be thus rather than otherwise. | |
From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 3.2) |
2104 | No reason could limit the quantity of matter, so there is no limit [Leibniz] |
Full Idea: There is no possible reason which could limit the quantity of matter; therefore there cannot in fact be any such limitation. | |
From: Gottfried Leibniz (Letters to Samuel Clarke [1716], 4.21) |
19342 | Reason avoids multiplying hypotheses or principles [Leibniz] |
Full Idea: Reason requires that we avoid multiplying hypotheses or principles, in somewhat the same way that the simplest system is always preferred in astronomy. | |
From: Gottfried Leibniz (Discourse on Metaphysics [1686], 5) | |
A reaction: He offers this principle without mentioning Ockham, as if it were self-evident. |
19426 | 'Nominal' definitions just list distinguishing characteristics [Leibniz] |
Full Idea: A 'nominal' definition is nothing more than an enumeration of the sufficient distinguishing characteristics. | |
From: Gottfried Leibniz (Reflections on Knowledge, Truth and Ideas [1684], p.284) | |
A reaction: Not wholly clear. Are these actual distinguishing characteristics, or potential ones? Could DNA be part of a human's nominal definition (for an unidentified corpse, perhaps). |
12983 | A nominal definition is of the qualities, but the real definition is of the essential inner structure [Leibniz] |
Full Idea: The essence of gold is what constitutes it and gives it the sensible qualities which let us recognize it and which make its nominal definition; but if we could explain this structure or inner constitution we would possess the real, causal definition. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.03) | |
A reaction: This is the view which I am championing, particularly in the role of explanation in the whole game. Explanation and understanding are the hallmarks of the discovery of a real essence. However, a falsehood may explain things well. Tricky. |
12915 | Definitions can only be real if the item is possible [Leibniz] |
Full Idea: Definitions to my mind are real, when one knows that the thing defined is possible; otherwise they are only nominal, and one must not rely on them. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 XI) | |
A reaction: It is interesting that things do not have to actual to have real definitions. For Leibniz, what is possible will exist in the mind of God. For me what is possible will exist in the potentialities of the powers of what is actual. |
12976 | If our ideas of a thing are imperfect, the thing can have several unconnected definitions [Leibniz] |
Full Idea: The result of having an imperfect idea of something is that the same subject admits of several mutually independent definitions: we shall sometimes be unable to derive one from another, or see in advance that they must belong to a single subject. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 2.31) | |
A reaction: See Idea 12975 for imperfect ideas of things. Obviously the idea is that perfect knowledge will converge on a single definition, which will pinpoint the essence of a thing, and then all explanations will flow. A nice addition to the Aristotelian view. |
12982 | One essence can be expressed by several definitions [Leibniz] |
Full Idea: Although a thing has only one essence, this can be expressed by several definitions. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.03) | |
A reaction: See Idea 12976 and Idea 12977 for a view which seems to conflict with this. He seemed to imply that once you identify the essence, the definitions converge, with multiple definitions being symptomatic of imperfect ideas of things. |
12984 | Real definitions, unlike nominal definitions, display possibilities [Leibniz] |
Full Idea: The real definition displays the possibility of the definiendum, and the nominal definition does not. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.03) | |
A reaction: This, I take it, is because the real definition indicates the actual powers of the thing, and not just the superficial characteristics. Is knowledge of powers identical with knowledge of possibilities? |
12980 | Genus and differentia might be swapped, and 'rational animal' become 'animable rational' [Leibniz] |
Full Idea: The genus can very often be turned into the differentia, ...so that in place of saying that man is a 'reasonable animal' we could, if language permitted, say that man is an 'animable rational', a rational substance with animal nature. | |
From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.03) | |
A reaction: This is a very telling point which rather undermines any dogmatic approach to what Aristotle says about these sorts of definitions. I don't find this account of definitions very helpful anyway. Leibniz links it to the order of cataloguing. |
8627 | Leibniz is inclined to regard all truths as provable [Leibniz, by Frege] |
Full Idea: Leibniz has an inclination to regard all truths as provable. | |
From: report of Gottfried Leibniz (works [1690]) by Gottlob Frege - Grundlagen der Arithmetik (Foundations) §15 | |
A reaction: Leibniz sounds like the epitome of Enlightenment optimism about the powers of reason. Could God prove every truth? It's a nice thought. |