Combining Philosophers

Ideas for H.Putnam/P.Oppenheim, Gottfried Leibniz and Anon (Lev)

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14 ideas

27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Bodies are recreated in motion, and don't exist in intervening instants [Leibniz]
     Full Idea: I have demonstrated that whatever moves is continuously created and that bodies are nothing at any time between the instants in motion.
     From: Gottfried Leibniz (Letters to Thomasius [1669], 1669.04), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 1
     A reaction: Leibniz is a little over-confident about what he has 'demonstrated', but I think (from this remark) that he would not have been displeased with quantum theory, and the notion of a 'quantum leap' and a 'Planck time'. A 'conatus' is a 'smallest motion'.
All that is real in motion is the force or power which produces change [Leibniz]
     Full Idea: As for motion, what is real in it is force or power; that is to say, what there is in the present state which carries with it a change in the future. The rest is only phenomena and relations.
     From: Gottfried Leibniz (Letter to the Editor about Bayle [1698], §13)
     A reaction: This presumably contradicts Newton's concept of inertia, which allows constant motion without force. I always like a reference to powers. What is 'kinetic energy' in this context?
Maybe motion is definable as 'change of place' [Leibniz]
     Full Idea: I believe 'motion' to be definable, and the definition which says that it is 'change of place' deserves respect.
     From: Gottfried Leibniz (New Essays on Human Understanding [1704], 3.04)
     A reaction: This seems to be the 'at-at' view of motion, championed by Bertrand Russell. (At p1 at t1, at p2 at t2...). Leibniz's version only mentions space and not time, and it includes 'change', which would need definition without mentioning motion.
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
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.
Leibniz uses 'force' to mean both activity and potential [Leibniz]
     Full Idea: At this early period exegetical problems abound, since Leibniz uses 'force' both for actually acting forces and for potentials or powers.
     From: Gottfried Leibniz (works [1690], 9.II), quoted by Harré,R./Madden,E.H. - Causal Powers 9.II.B
     A reaction: I take Leibniz to be a key figure in the development of the Aristotelian approach, because he connected Aristotelian potential and essence with 'force' in the new physics. This is helpful in reading him correctly.
Clearly, force is that from which action follows, when unimpeded [Leibniz]
     Full Idea: The notion of force is as clear as that of action and passion, because it is that from which action follows when nothing prevents it.
     From: Gottfried Leibniz (Letters to Paul Pellison-Fontinier [1691], A1.6.226), quoted by Daniel Garber - Leibniz:Body,Substance,Monad 4
     A reaction: For Leibniz, force seems to be a metaphysical notion, rather than a feature of the physical world. I take it to be the bottom level of explanation, and it equates with Aristotelian form and essence.
We need the metaphysical notion of force to explain mechanics, and not just extended mass [Leibniz]
     Full Idea: Considering 'extended mass' alone was not sufficient to explain the principles of mechanics and the laws of nature, but it is necessary to make use of the notion of 'force', which is very intelligible, despite belonging in the domain of metaphysics.
     From: Gottfried Leibniz (New system of communication of substances [1695], p.139)
     A reaction: We may find it surprising that force is a metaphysical concept, but that is worth pondering. It is a mysterious notion within physics. Notice the emphasis on what explains, and what is intelligible. He sees Descartes's system as too passive.
All qualities of bodies reduce to forces [Leibniz]
     Full Idea: All qualities of bodies .....are in the end reduced [revoco] to forces.
     From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.256)
     A reaction: The dots conceal a long qualification, but he is essentially standing by this simple remark. If you substitute the word 'powers' for 'forces', I think that is just about right.
It is plausible to think substances contain the same immanent force seen in our free will [Leibniz]
     Full Idea: If we attribute an inherent force to our mind, a force acting immanently, then nothing forbids us to suppose that the same force would be found in other souls or forms, or, if you prefer, in the nature of substances.
     From: Gottfried Leibniz (On Nature Itself (De Ipsa Natura) [1698], §10)
     A reaction: This is the kind of bizarre idea that you are driven to, once you start thinking that God must have a will outside nature, and then that we have the same thing. Why shouldn't such a thing pop up all over the place? Only Leibniz spots the slippery slope.
Power is passive force, which is mass, and active force, which is entelechy or form [Leibniz]
     Full Idea: The dynamicon or power [potentia] in bodies is twofold, passive and active. Passive force [vis] constitutes matter or mass [massa], and active force constitutes entelechy or form.
     From: Gottfried Leibniz (On Body and Force, Against the Cartesians [1702], p.252)
     A reaction: This is explicitly equating the innate force understood in physics with Aristotelian form. The passive force is to explain the resistance of bodies. I like the equation of force with power. He says the entelechy is 'analogous' to a soul.
The force behind motion is like a soul, with its own laws of continual change [Leibniz]
     Full Idea: I recognise, in the active force which exerts itself through motion, the primitive entelechy or in a word, something analogous to the soul, whose nature consists in a certain perpetual law of the same series of changes through which it runs unhindered.
     From: Gottfried Leibniz (Letters to Burcher De Volder [1706], 1699), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 6.1.3
     A reaction: This is a hugely metaphysical account of force, contrasting with Newton's largely mathematical account. He very often says that force is 'analogous' to the soul, rather than that it actually is a soul. He never quite believes that monads are real minds.
Force in substance makes state follow state, and ensures the very existence of substance [Leibniz]
     Full Idea: By the force I give to substances, I understand a state from which another state follows, if nothing prevents it. ...I dare say that without force, there would be no substance.
     From: Gottfried Leibniz (Letters to Lelong [1712], 1712), quoted by Cover,J/O'Leary-Hawthorne,J - Substance and Individuation in Leibniz 7.1
     A reaction: [the whole quote is interesting] This remark, more than any other I have found, places force at the centre of Leibniz's metaphysics. He is using it to resist Spinoza's one-substance view.
Some people return to scholastic mysterious qualities, disguising them as 'forces' [Leibniz]
     Full Idea: It pleases others to return to occult qualities or scholastic faculties, but since these crude philosophers and physicians see that those terms are in bad repute they change their name, calling them 'forces'.
     From: Gottfried Leibniz (Against Barbaric physics [1716], A&G:313), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 19.7
     A reaction: Deceptive, because Leibniz embraced forces in his revised Aristotelian essentialism. Leibniz placed forces within essences, and he is worried about forces as separate entities, unsupported by any substance.
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / c. Conservation of energy
Leibniz upheld conservations of momentum and energy [Leibniz, by Papineau]
     Full Idea: In place of Descartes's conservation of 'quantity of motion', Leibniz upheld both the conservation of linear momentum and the conservation of kinetic energy.
     From: report of Gottfried Leibniz (Letters to Samuel Clarke [1716], 5th paper) by David Papineau - Thinking about Consciousness App 2
     A reaction: The point is that momentum involves velocity (which includes direction) rather than speed. Leibniz more or less invented the concept of 'energy' ('vis viva'). Papineau says these two leave no room for causation by mental substance.