48 ideas
12926 | Wisdom is the science of happiness [Leibniz] |
Full Idea: Wisdom is the science of happiness. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1690.03.23) | |
A reaction: That probably comes down to common sense, or Aristotle's 'phronesis'. I take wisdom to involve understanding, as well as the quest for happiness. |
12903 | Wise people have fewer acts of will, because such acts are linked together [Leibniz] |
Full Idea: The wiser one is, the fewer separate acts of will one has and the more one's views and acts of will are comprehensive and linked together. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.04.12) | |
A reaction: [letter to Landgrave, about Arnauld] It is unusual to find a philosopher who actually tries to analyse the nature of wisdom, instead of just paying lipservice to it. I take Leibniz to be entirely right here. He equates wisdom with rational behaviour. |
12914 | Metaphysics is geometrical, resting on non-contradiction and sufficient reason [Leibniz] |
Full Idea: I claim to give metaphysics geometric demonstrations, assuming only the principle of contradiction (or else all reasoning becomes futile), and that nothing exists without a reason, or that every truth has an a priori proof, from the concept of terms. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 XI) | |
A reaction: For the last bit, see Idea 12910. This idea is the kind of huge optimism about metaphysic which got it a bad name after Kant, and in modern times. I'm optimistic about metaphysics, but certainly not about 'geometrical demonstrations' of it. |
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. |
12910 | The predicate is in the subject of a true proposition [Leibniz] |
Full Idea: In a true proposition the concept of the predicate is always present in the subject. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X) | |
A reaction: This sounds very like the Kantian notion of an analytic truth, but Leibniz is applying it to all truths. So Socrates must contain the predicate of running as part of his nature (or essence?), if 'Socrates runs' is to be true. |
19333 | A truth is just a proposition in which the predicate is contained within the subject [Leibniz] |
Full Idea: In every true affirmative proposition, necessary or contingent, universal or particular, the concept of the predicate is in a sense included in that of the subject; the predicate is present in the subject; or else I do not know what truth is. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14) | |
A reaction: Why did he qualify this with "in a sense"? This is referred to as the 'concept containment theory of truth'. This is an odd view of the subject. If the truth is 'Peter fell down stairs', we don't usually think the concept of Peter contains such things. |
7557 | To solve Zeno's paradox, reject the axiom that the whole has more terms than the parts [Russell] |
Full Idea: Presumably Zeno appealed to the axiom that the whole has more terms than the parts; so if Achilles were to overtake the tortoise, he would have been in more places than the tortoise, which he can't be; but the conclusion is absurd, so reject the axiom. | |
From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.89) | |
A reaction: The point is that the axiom is normally acceptable (a statue contains more particles than the arm of the statue), but it breaks down when discussing infinity (Idea 7556). Modern theories of infinity are needed to solve Zeno's Paradoxes. |
10059 | In mathematic we are ignorant of both subject-matter and truth [Russell] |
Full Idea: Mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true. | |
From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.76) | |
A reaction: A famous remark, though Musgrave is rather disparaging about Russell's underlying reasoning here. |
12920 | There is no multiplicity without true units [Leibniz] |
Full Idea: There is no multiplicity without true units. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30) | |
A reaction: Hence real numbers do not embody 'multiplicity'. So either they don't 'embody' anything, or they embody 'magnitudes'. Does this give two entirely different notions, of measure of multiplicity and measures of magnitude? |
7556 | A collection is infinite if you can remove some terms without diminishing its number [Russell] |
Full Idea: A collection of terms is infinite if it contains as parts other collections which have as many terms as it has; that is, you can take away some terms of the collection without diminishing its number; there are as many even numbers as numbers all together. | |
From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.86) | |
A reaction: He cites Dedekind and Cantor as source for these ideas. If it won't obey the rule that subtraction makes it smaller, then it clearly isn't a number, and really it should be banned from all mathematics. |
12319 | What is not truly one being is not truly a being either [Leibniz] |
Full Idea: What is not truly one being is not truly a being either. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30), quoted by Alain Badiou - Briefings on Existence 1 | |
A reaction: Badiou quotes this as identifying Being with the One. I say Leibniz had no concept of 'gunk', and thought everything must have a 'this' identity in order to exist, which is just the sort of thing a logician would come up with. |
12922 | A thing 'expresses' another if they have a constant and fixed relationship [Leibniz] |
Full Idea: One thing 'expresses' another (in my terminology) when there exists a constant and fixed relationship between what can be said of one and of the other. This is the way that a perspectival projection expresses its ground-plan. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.10.09) | |
A reaction: Arnauld was puzzled by what Leibniz might mean by 'express', and it occurs to me that Leibniz was fishing for the modern concept of 'supervenience'. It also sounds a bit like the idea of 'covariance' between mind and world. Maybe he means 'function'. |
13079 | A substance contains the laws of its operations, and its actions come from its own depth [Leibniz] |
Full Idea: Each indivisible substance contains in its nature the law by which the series of its operations continues, and all that has happened and will happen to it. All its actions come from its own depths, except for dependence on God. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1688.01.4/14) | |
A reaction: I take the combination of 'laws' and 'forces', which Leibniz attributes to Aristotelian essences, to be his distinctive contribution towards giving us an Aristotelian metaphysic which is suitable for modern science. |
12745 | Philosophy needs the precision of the unity given by substances [Leibniz] |
Full Idea: Philosophy cannot be better reduced to something precise, than by recognising only substances or complete beings endowed with a true unity, with different states that succeed one another; all else is phenomena, abstractions or relations. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 7 | |
A reaction: This idea bothers me. Has the whole of modern philosophy been distorted by this yearning for 'precision'? It has put mathematicians and logicians in the driving seat. Do we only attribute unity because it suits our thinking? |
12921 | Accidental unity has degrees, from a mob to a society to a machine or organism [Leibniz] |
Full Idea: There are degrees of accidental unity, and an ordered society has more unity than a chaotic mob, and an organic body or a machine has more unity than a society. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30) | |
A reaction: This immediately invites questions about the extremes. Why does the very highest degree of 'accidental unity' not achieve 'true unity'? And why cannot a very ununified aggregate have a bit of unity (as in unrestricted mereological composition)? |
12746 | We find unity in reason, and unity in perception, but these are not true unity [Leibniz] |
Full Idea: A pair of diamonds is merely an entity of reason, and even if one of them is brought close to another, it is an entity of imagination or perception, that is to say a phenomenon; contiguity, common movement and the same end don't make substantial unity. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 7 | |
A reaction: This invites the question of what you have to do to two objects to give them substantial unity. The distinction between unity 'of reason' and unity 'of perception' is good. |
12916 | A body is a unified aggregate, unless it has an indivisible substance [Leibniz] |
Full Idea: One will never find a body of which it may be said that it is truly one substance, ...because entities made up by aggregation have only as much reality as exists in the constituent parts. Hence the substance of a body must be indivisible. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.11) | |
A reaction: Leibniz rejected atomism, and he evidently believed that pure materialists must deny the real existence of physical objects. Common sense suggests that causal bonds bestow a high degree of unity on bodies (if degrees are allowed). |
12919 | Unity needs an indestructible substance, to contain everything which will happen to it [Leibniz] |
Full Idea: Substantial unity requires a complete, indivisible and naturally indestructible entity, since its concept embraces everything that is to happen to it, which cannot be found in shape or motion. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.11.28/12.8) | |
A reaction: Hence if a tile is due to be broken in half (Arnauld's example), it cannot have had unity in the first place. To what do we refer when we say 'the tile was broken'? |
12923 | Every bodily substance must have a soul, or something analogous to a soul [Leibniz] |
Full Idea: Every bodily substance must have a soul, or at least an entelechy which is analogous to the soul. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.10.09) | |
A reaction: He routinely commits to a 'soul', and then pulls back and says it may only be an 'analogy'. He had deep doubts about his whole scheme, which emerged in the late correspondence with Des Bosses. This not monads, says Garber. |
12704 | Aggregates don’t reduce to points, or atoms, or illusion, so must reduce to substance [Leibniz] |
Full Idea: In aggregates one must necessarily arrive either at mathematical points from which some make up extension, or at atoms (which I dismiss), or else no reality can be found in bodies, or finally one must recognises substances that possess a true unity. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 2 | |
A reaction: Garber calls this Leibniz's Aggregate Argument. Leibniz is, of course, talking of physical aggregates which have unity. He consistently points out that a pile of logs has no unity at all. But is substance just that-which-provides-unity? |
13077 | Basic predicates give the complete concept, which then predicts all of the actions [Leibniz] |
Full Idea: Apart from those that depend on others, one must only consider together all the basic predicates in order to form the complete concept of Adam adequate to deduce from it everything that is ever to happen to him, as much as is necessary to account for it. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06) | |
A reaction: This (implausibly) goes beyond mere prediction of properties. Eve's essence seems to be relevant to Adam's life. Note that the complete concept is not every predicate, but only those 'necessary' to predict the events. Cf Idea 13082. |
12908 | Essences exist in the divine understanding [Leibniz] |
Full Idea: Essences exist in the divine understanding before one considers will. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X) | |
A reaction: This is a sort of religious neo-platonism. The great dream seems to be that of mind-reading God, and the result is either Pythagoras (it's numbers!), or Plato (it's pure ideas!), or this (it's essences!). See D.H.Lawrence's poem on geranium and mignottes. |
12706 | Bodies need a soul (or something like it) to avoid being mere phenomena [Leibniz] |
Full Idea: Every substance is indivisible and consequently every corporeal substance must have a soul or at least an entelechy which is analogous to the soul, since otherwise bodies would be no more than phenomena. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], G II 121), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 2 | |
A reaction: There is a large gap between having 'a soul' and having something 'analogous to a soul'. I take the analogy to be merely as originators of action. Leibniz wants to add appetite and sensation to the Aristotelian forms (but knows this is dubious!). |
12906 | Truths about species are eternal or necessary, but individual truths concern what exists [Leibniz] |
Full Idea: The concept of a species contains only eternal or necessary truths, whereas the concept of an individual contains, regarded as possible, what in fact exists or what is related to the existence of things and to time. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06) | |
A reaction: This seems to be what is behind the preference some have for kind-essences rather than individual essences. But the individual must be explained, as well as the kind. Not all tigers are identical. The two are, of course, compatible. |
12904 | If varieties of myself can be conceived of as distinct from me, then they are not me [Leibniz] |
Full Idea: I can as little conceive of different varieties of myself as of a circle whose diameters are not all of equal length. These variations would all be distinct one from another, and thus one of these varieties of myself would necessarily not be me. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.05.13) | |
A reaction: This seems to be, at the very least, a rejection of any idea that I could have a 'counterpart'. It is unclear, though, where he would place a version of himself who learned a new language, or who might have had, but didn't have, a haircut. |
11981 | If someone's life went differently, then that would be another individual [Leibniz] |
Full Idea: If the life of some person, or something went differently than it does, nothing would stop us from saying that it would be another person, or another possible universe which God had chosen. So truly it would be another individual. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.14) | |
A reaction: Plantinga quotes this as an example of 'worldbound individuals'. This sort of remark leads to people saying that Leibniz believes all properties are essential, since they assume that his notion of essence is bound up with identity. But is it? |
12905 | I cannot think my non-existence, nor exist without being myself [Leibniz] |
Full Idea: I am assured that as long as I think, I am myself. For I cannot think that I do not exist, nor exist so that I be not myself. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.05.13) | |
A reaction: Elsewhere he qualifies the Cogito, but here he seems to straighforwardly endorse it. |
19334 | I can't just know myself to be a substance; I must distinguish myself from others, which is hard [Leibniz] |
Full Idea: It is not enough for understanding the nature of myself, that I feel myself to be a thinking substance, one would have to form a distinct idea of what distinguishes me from all other possible minds; but of that I have only a confused experience. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14) | |
A reaction: Not a criticism I have encountered before. Does he mean that I might be two minds, or might be a multitude of minds? It seems to be Hume's problem, that you are aware of experiences, but not of the substance that unites them. |
7554 | Self-evidence is often a mere will-o'-the-wisp [Russell] |
Full Idea: Self-evidence is often a mere will-o'-the-wisp, which is sure to lead us astray if we take it as our guide. | |
From: Bertrand Russell (Mathematics and the Metaphysicians [1901], p.78) | |
A reaction: The sort of nice crisp remark you would expect from a good empiricist philosopher. Compare Idea 4948. However Russell qualifies it with the word 'often', and all philosophers eventually realise that you have to start somewhere. |
5033 | Nothing should be taken as certain without foundations [Leibniz] |
Full Idea: Nothing should be taken as certain without foundations. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.04.30) | |
A reaction: This might leave open the option, if you were a modern 'Fallibilist', that something might lack foundations, and so not be certain, and yet still qualify as 'knowledge'. That is my view. Knowledge resides somewhere between opinion and certainty. |
12913 | Nature is explained by mathematics and mechanism, but the laws rest on metaphysics [Leibniz] |
Full Idea: One must always explain nature along mathematical and mechanical lines, provided one knows that the very principles or laws of mechanics or of force do not depend upon mathematical extension alone but upon certain metaphysical reasons. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X) | |
A reaction: I like this, and may even use it as the epigraph of my masterwork. Recently Stephen Hawking (physicist) has been denigrating philosophy, but I am with Leibniz on this one. |
13089 | To fully conceive the subject is to explain the resulting predicates and events [Leibniz] |
Full Idea: Even in the most contingent truths, there is always something to be conceived in the subject which serves to explain why this predicate or event pertains to it, or why this has happened rather than not. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06) | |
A reaction: The last bit, about containing what has happened, seems absurd, but the rest of it makes sense. It is just the Aristotelian essentialist view, that a full understanding of the inner subject will both explain and predict the surface properties. |
5034 | Mind is a thinking substance which can know God and eternal truths [Leibniz] |
Full Idea: Minds are substances which think, and are capable of knowing God and of discovering eternal truths. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1687.10.09) | |
A reaction: 'God' is there because the ability to grasp the ontological argument is seen as basic. Note a firm commitment to substance-dualism, and a rationalist commitment to the spotting of necessary truths as basic. He is not totally wrong. |
5032 | It seems probable that animals have souls, but not consciousness [Leibniz] |
Full Idea: It appears probable that the brutes have souls, though they are without consciousness. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.12.08) | |
A reaction: This will be a response to Descartes, who allowed animals sensations, but not minds or souls. Personally I cannot make head or tail of Leibniz's claim. What makes it "apparent" to him? |
5031 | Everything which happens is not necessary, but is certain after God chooses this universe [Leibniz] |
Full Idea: It is not the case that everything which happens is necessary; rather, everything which happens is certain after God made choice of this possible universe, whose notion contains this series of things. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.05) | |
A reaction: I think this distinction is best captured as 'metaphysical necessity' (Leibniz's 'necessity'), and 'natural necessity' (his 'certainty'). 'Certainty' seems a bad word, as it is either certain de dicto or de re. Is God certain, or is the thing certain? |
12911 | Concepts are what unite a proposition [Leibniz] |
Full Idea: There must always be some basis for the connexion between the terms of a proposition, and it is to be found in their concepts. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X) | |
A reaction: We face the problem that bothered Russell, of the unity of the proposition. We are also led to the question of HOW our concepts connect the parts of a proposition. Do concepts have valencies? Are they incomplete, as Frege suggests? |
12925 | Beauty increases with familiarity [Leibniz] |
Full Idea: The more one is familiar with things, the more beautiful one finds them. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1688.01.4/14) | |
A reaction: This is always the reply given to those who say that science kills our sense of beauty. The first step in aesthetic life is certainly to really really pay attention to things. |
12927 | Happiness is advancement towards perfection [Leibniz] |
Full Idea: Happiness, or lasting contentment, consists of continual advancement towards a greater perfection. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1690.03.23) | |
A reaction: To the modern mind this smacks of the sort of hubris to which only the religious mind can aspire, but it's still rather nice. The idea of grubby little mammals approaching perfection sounds wrong, but which other animal has even thought of perfection? |
541 | Virtue comes more from habit than character [Critias] |
Full Idea: More men are good through habit than through character. | |
From: Critias (fragments/reports [c.440 BCE], B09), quoted by John Stobaeus - Anthology 3.29.41 |
15955 | I think the corpuscular theory, rather than forms or qualities, best explains particular phenomena [Leibniz] |
Full Idea: I still subscribe fully to the corpuscular theory in the explanation of particular phenomena; in this sphere it is of no value to speak of forms or qualities. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 14.07.1686) | |
A reaction: I am puzzled by Garber's summary in Idea 12728, and a bit unclear on Leibniz's views on atoms. More needed. |
12907 | Each possible world contains its own laws, reflected in the possible individuals of that world [Leibniz] |
Full Idea: As there exist an infinite number of possible worlds, there exists also an infinite number of laws, some peculiar to one world, some to another, and each individual of any one world contains in the concept of him the laws of his world. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.06) | |
A reaction: Since Leibniz's metaphysics is thoroughly God-driven, he will obviously allow God to create any laws He wishes, and hence scientific essentialism seems to be rejected, even though Leibniz is keen on essences. Unless the stuff is different... |
12924 | Motion alone is relative, but force is real, and establishes its subject [Leibniz] |
Full Idea: Motion in itself separated from force is merely relative, and one cannot establish its subject. But force is something real and absolute. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1688.01.4/14) | |
A reaction: The striking phrase here is that force enables us to 'establish its subject'. That is, force is at the heart of reality, and hence, through causal relations, individuates objects. That's how I read it. |
12909 | Everything, even miracles, belongs to order [Leibniz] |
Full Idea: Everything, even miracles, belongs to order. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X) | |
A reaction: This is very reminiscent of Plato, for whom there was no more deeply held belief than that the cosmos is essentially orderly. Coincidences are a nice problem, if they are events with no cause. |
5030 | Miracles are extraordinary operations by God, but are nevertheless part of his design [Leibniz] |
Full Idea: Miracles, or the extraordinary operations of God, none the less belong within the general order; they are in conformity with the principal designs of God, and consequently are included in the notion of this universe, which is the result of those designs. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.05) | |
A reaction: Some philosophers just make up things to suit themselves. What possible grounds can he have for claiming this? At best this is tautological, saying that, by definition, if anything at all happens, it must be part of God's design. Move on to Hume… |
542 | Fear of the gods was invented to discourage secret sin [Critias] |
Full Idea: When the laws forbade men to commit open crimes of violence, and they began to do them in secret, a wise and clever man invented fear of the gods for mortals, to frighten the wicked, even if they sin in secret. | |
From: Critias (fragments/reports [c.440 BCE], B25), quoted by Sextus Empiricus - Against the Professors (six books) 9.54 |
12912 | Immortality without memory is useless [Leibniz] |
Full Idea: Immortality without memory would be useless. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.07.4/14 X) | |
A reaction: I would say that having a mind of any sort needs memory. The question for immortality is whether it extends back to human life. See 'Wuthering Heights' (c. p90) for someone who remembers Earth as so superior to paradise that they long to return there. |
12917 | The soul is indestructible and always self-aware [Leibniz] |
Full Idea: Not only is the soul indestructible, but it always knows itself and remains self-conscious. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.11) | |
A reaction: Personally I am not even self-aware during much of my sleeping hours, and I would say that I cease to be self-aware if I am totally absorbed in something on which I concentrate. |
12918 | Animals have souls, but lack consciousness [Leibniz] |
Full Idea: It appears probable that animals have souls although they lack consciousness. | |
From: Gottfried Leibniz (Letters to Antoine Arnauld [1686], 1686.11) | |
A reaction: Personally I would say that they lack souls but have consciousness, but then I am in no better position to know the answer than Leibniz was. Arnauld asks what would happen to the souls of 100,000 silkworms if they caught fire! |