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All the ideas for 'works', 'Principles of Philosophy' and 'Scepticism'

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54 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
For Plato true wisdom is supernatural [Plato, by Weil]
     Full Idea: It is evident that Plato regards true wisdom as something supernatural.
     From: report of Plato (works [c.375 BCE]) by Simone Weil - God in Plato p.61
     A reaction: Taken literally, I assume this is wrong, but we can empathise with the thought. Wisdom has the feeling of rising above the level of mere knowledge, to achieve the overview I associate with philosophy.
1. Philosophy / C. History of Philosophy / 2. Ancient Philosophy / b. Pre-Socratic philosophy
Plato never mentions Democritus, and wished to burn his books [Plato, by Diog. Laertius]
     Full Idea: Plato, who mentions nearly all the ancient philosophers, nowhere speaks of Democritus; he wished to burn all of his books, but was persuaded that it was futile.
     From: report of Plato (works [c.375 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 09.7.8
1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
The greatest good for a state is true philosophers [Descartes]
     Full Idea: The greatest good which can exist in a state is to have true philosophers.
     From: René Descartes (Principles of Philosophy [1646], Pref)
     A reaction: …because they understand true reality, especially the Good.
2. Reason / C. Styles of Reason / 1. Dialectic
Two contradictories force us to find a relation which will correlate them [Plato, by Weil]
     Full Idea: Where contradictions appear there is a correlation of contraries, which is relation. If a contradiction is imposed on the intelligence, it is forced to think of a relation to transform the contradiction into a correlation, which draws the soul higher.
     From: report of Plato (works [c.375 BCE]) by Simone Weil - God in Plato p.70
     A reaction: A much better account of the dialectic than anything I have yet seen in Hegel. For the first time I see some sense in it. A contradiction is not a falsehood, and it must be addressed rather than side-stepped. A kink in the system, that needs ironing.
8. Modes of Existence / A. Relations / 3. Structural Relations
Plato's idea of 'structure' tends to be mathematically expressed [Plato, by Koslicki]
     Full Idea: 'Structure' tends to be characterized by Plato as something that is mathematically expressed.
     From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects V.3 iv
     A reaction: [Koslicki is drawing on Verity Harte here]
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
All powers can be explained by obvious features like size, shape and motion of matter [Descartes]
     Full Idea: There are no powers in stones and plants that are not so mysterious that they cannot be explained …from principles that are known to all and admitted by all, namely the shape, size, position, and motion of particles of matter.
     From: René Descartes (Principles of Philosophy [1646], IV.187), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 23.6
     A reaction: This is an invocation of 'categorical' properties, against dispositions. I take this to be quite wrong. The explanation goes the other way. What supports the structures; what drives the motion; what initiates anything?
8. Modes of Existence / D. Universals / 1. Universals
Five universals: genus, species, difference, property, accident [Descartes]
     Full Idea: The five commonly enumerated universals are: genus, species, difference, property and accident.
     From: René Descartes (Principles of Philosophy [1646], I.59)
     A reaction: Interestingly, this seems to be Descartes passing on his medieval Aristotelian inheritance, in which things are defined by placing them in a class, and then noting what distinguishes them within that class.
8. Modes of Existence / D. Universals / 6. Platonic Forms / a. Platonic Forms
When Diogenes said he could only see objects but not their forms, Plato said it was because he had eyes but no intellect [Plato, by Diog. Laertius]
     Full Idea: When Diogenes told Plato he saw tables and cups, but not 'tableness' and 'cupness', Plato replied that this was because Diogenes had eyes but no intellect.
     From: report of Plato (works [c.375 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 06.2.6
Platonists argue for the indivisible triangle-in-itself [Plato, by Aristotle]
     Full Idea: The Platonists, on the basis of purely logical arguments, posit the existence of an indivisible 'triangle in itself'.
     From: report of Plato (works [c.375 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 316a15
     A reaction: A helpful confirmation that geometrical figures really are among the Forms (bearing in mind that numbers are not, because they contain one another). What shape is the Form of the triangle?
Plato's Forms meant that the sophists only taught the appearance of wisdom and virtue [Plato, by Nehamas]
     Full Idea: Plato's theory of Forms allowed him to claim that the sophists and other opponents were trapped in the world of appearance. What they therefore taught was only apparent wisdom and virtue.
     From: report of Plato (works [c.375 BCE]) by Alexander Nehamas - Eristic,Antilogic,Sophistic,Dialectic p.118
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
If there is one Form for both the Form and its participants, they must have something in common [Aristotle on Plato]
     Full Idea: If there is the same Form for the Forms and for their participants, then they must have something in common.
     From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 991a
8. Modes of Existence / D. Universals / 6. Platonic Forms / c. Self-predication
If gods are like men, they are just eternal men; similarly, Forms must differ from particulars [Aristotle on Plato]
     Full Idea: We say there is the form of man, horse and health, but nothing else, making the same mistake as those who say that there are gods but that they are in the form of men. They just posit eternal men, and here we are not positing forms but eternal sensibles.
     From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 997b
8. Modes of Existence / D. Universals / 6. Platonic Forms / d. Forms critiques
A Form is a cause of things only in the way that white mixed with white is a cause [Aristotle on Plato]
     Full Idea: A Form is a cause of things only in the way that white mixed with white is a cause.
     From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 991a
The Forms cannot be changeless if they are in changing things [Aristotle on Plato]
     Full Idea: The Forms could not be changeless if they were in changing things.
     From: comment on Plato (works [c.375 BCE]) by Aristotle - Metaphysics 998a
8. Modes of Existence / E. Nominalism / 2. Resemblance Nominalism
A universal is a single idea applied to individual things that are similar to one another [Descartes]
     Full Idea: Universals arise solely from the fact that we avail ourselves of one idea in order to think of all individual things that have a certain similitude. When we understand under the same name all the objects represented by this idea, that name is universal.
     From: René Descartes (Principles of Philosophy [1646], I.59)
     A reaction: Judging by the boldness of the pronouncement, it looks as if Descartes hasn't recognised the complexity of the problem. How do we spot a 'similarity', especially an abstraction like 'tool' or 'useful'? This sounds like Descartes trying to avoid Platonism.
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
The greatest discovery in human thought is Plato's discovery of abstract objects [Brown,JR on Plato]
     Full Idea: The greatest discovery in the history of human thought is Plato's discovery of abstract objects.
     From: comment on Plato (works [c.375 BCE]) by James Robert Brown - Philosophy of Mathematics Ch. 2
     A reaction: Compare Idea 2860! Given the diametrically opposed views, it is clearly likely that Plato's central view is the most important idea in the history of human thought, even if it is wrong.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
We can grasp whole things in science, because they have a mathematics and a teleology [Plato, by Koslicki]
     Full Idea: Due to the mathematical nature of structure and the teleological cause underlying the creation of Platonic wholes, these wholes are intelligible, and are in fact the proper objects of science.
     From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.3
     A reaction: I like this idea, because it pays attention to the connection between how we conceive objects to be, and how we are able to think about objects. Only examining these two together enables us to grasp metaphysics.
9. Objects / B. Unity of Objects / 1. Unifying an Object / a. Intrinsic unification
Plato sees an object's structure as expressible in mathematics [Plato, by Koslicki]
     Full Idea: The 'structure' of an object tends to be characterised by Plato as something that is mathematically expressible.
     From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.3
     A reaction: This seems to be pure Pythagoreanism (see Idea 644). Plato is pursuing Pythagoras's research programme, of trying to find mathematics buried in every aspect of reality.
Plato was less concerned than Aristotle with the source of unity in a complex object [Plato, by Koslicki]
     Full Idea: Plato was less concerned than Aristotle with the project of how to account, in completely general terms, for the source of unity within a mereologically complex object.
     From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.5
     A reaction: Plato seems to have simply asserted that some sort of harmony held things together. Aristotles puts the forms [eidos] within objects, rather than external, so he has to give a fuller account of what is going on in an object. He never managed it!
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
If we perceive an attribute, we infer the existence of some substance [Descartes]
     Full Idea: Based on perceiving the presence of some attribute, we conclude there must also be present an existing thing or substance to which it can be attributed.
     From: René Descartes (Principles of Philosophy [1646], I.52), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.1
     A reaction: A rainbow might be a tricky case. This illustrates the persistent belief in substances, even among philosophers who embraced the new corpuscular and mechanistic view of matter.
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
Plato's holds that there are three substances: Forms, mathematical entities, and perceptible bodies [Plato, by Aristotle]
     Full Idea: Plato's doctrine was that the Forms and mathematicals are two substances and that the third substance is that of perceptible bodies.
     From: report of Plato (works [c.375 BCE]) by Aristotle - Metaphysics 1028b
9. Objects / B. Unity of Objects / 2. Substance / d. Substance defined
A substance needs nothing else in order to exist [Descartes]
     Full Idea: By substance we can understand nothing else than a thing which so exists that it needs no other thing in order to exist.
     From: René Descartes (Principles of Philosophy [1646], I.51)
     A reaction: Properties, of course, are the things which have dependent existence. Can properties be reduced to substances (e.g. by adopting a materialist theory of mind)? Note that Descartes does not think that substances depend on God for existence.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
Plato says wholes are either containers, or they're atomic, or they don't exist [Plato, by Koslicki]
     Full Idea: Plato considers a 'container' model for wholes (which are disjoint from their parts) [Parm 144e3-], and a 'nihilist' model, in which only wholes are mereological atoms, and a 'bare pluralities' view, in which wholes are not really one at all.
     From: report of Plato (works [c.375 BCE]) by Kathrin Koslicki - The Structure of Objects 5.2
     A reaction: [She cites Verity Harte for this analysis of Plato] The fourth, and best, seems to be that wholes are parts which fall under some unifying force or structure or principle.
9. Objects / D. Essence of Objects / 2. Types of Essence
Only universals have essence [Plato, by Politis]
     Full Idea: Plato argues that only universals have essence.
     From: report of Plato (works [c.375 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.4
9. Objects / D. Essence of Objects / 6. Essence as Unifier
Plato and Aristotle take essence to make a thing what it is [Plato, by Politis]
     Full Idea: Plato and Aristotle have a shared general conception of essence: the essence of a thing is what that thing is simply in virtue of itself and in virtue of being the very thing it is. It answers the question 'What is this very thing?'
     From: report of Plato (works [c.375 BCE]) by Vassilis Politis - Aristotle and the Metaphysics 1.4
9. Objects / D. Essence of Objects / 9. Essence and Properties
A substance has one principal property which is its nature and essence [Descartes]
     Full Idea: Each substance has one principal property that constitutes its nature and essence, to which all its other properties are referred. Extension in length, breadth, and depth constitutes the nature of corporeal substance; and thought of thinking substances.
     From: René Descartes (Principles of Philosophy [1646], I.53), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 08.3
     A reaction: Property is likely to be 'propria', which is a property distinctive of some thing, not just any old modern property. This is quite a strikingly original view of the nature of essence. Descartes despised 'substantial forms'.
11. Knowledge Aims / B. Certain Knowledge / 4. The Cogito
Total doubt can't include your existence while doubting [Descartes]
     Full Idea: He who decides to doubt everything cannot nevertheless doubt that he exists while he doubts.
     From: René Descartes (Principles of Philosophy [1646], Pref)
I think, therefore I am, because for a thinking thing to not exist is a contradiction [Descartes]
     Full Idea: There is a contradiction in conceiving that what thinks does not (at the same time as it thinks) exist. Hence this conclusion I think, therefore I am, is the first and most certain that occurs to one who philosophises in an orderly way.
     From: René Descartes (Principles of Philosophy [1646], I.07)
     A reaction: The classic statement of his argument. The significance here is that it seems to have the structure of an argument, as it involves 'philosophising', which leads to a 'contradiction', and hence to the famous conclusion. It is not just intuitive.
'Thought' is all our conscious awareness, including feeling as well as understanding [Descartes]
     Full Idea: By the word 'thought' I understand everything we are conscious of as operating in us. And that is why not only understanding, willing, imagining, but also feeling, are here the same thing as thinking.
     From: René Descartes (Principles of Philosophy [1646], I.09)
     A reaction: There is a bit of tension here between Descartes' correct need to include feeling in thought for his Cogito argument, and his tendency to dismiss animal consciousness, on the grounds that they only sense things, and don't make judgements.
12. Knowledge Sources / A. A Priori Knowledge / 4. A Priori as Necessities
'Nothing comes from nothing' is an eternal truth found within the mind [Descartes]
     Full Idea: The proposition 'nothing comes from nothing' is not to be considered as an existing thing, or the mode of a thing, but as a certain eternal truth which has its seat in our mind and is a common notion or axiom.
     From: René Descartes (Principles of Philosophy [1646], I.49)
     A reaction: There is a tension here, in his assertion that it is 'eternal', but 'not existing'. How does one distinguish an innate idea from an innate truth? 'Eternal' sounds like an external guarantee of truth, but being 'in our mind' sounds less reliable.
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / b. Basic beliefs
We can know basic Principles without further knowledge, but not the other way round [Descartes]
     Full Idea: It is on the Principles, or first causes, that the knowledge of other things depends, so the Principles can be known without these last, but the other things cannot reciprocally be known without the Principles.
     From: René Descartes (Principles of Philosophy [1646], Pref)
     A reaction: A particularly strong assertion of foundationalism, as it says that not only must the foundations exist, but also we must actually know them. This sounds false, as elementary knowledge then seems to require far too much sophistication.
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
A good explanation totally rules out the opposite explanation (so Forms are required) [Plato, by Ruben]
     Full Idea: For Plato, an acceptable explanation is one such that there is no possibility of there being the opposite explanation at all, and he thought that only explanations in terms of the Forms, but never physical explanations, could meet this requirement.
     From: report of Plato (works [c.375 BCE]) by David-Hillel Ruben - Explaining Explanation Ch 2
     A reaction: [Republic 436c is cited]
15. Nature of Minds / B. Features of Minds / 1. Consciousness / b. Essence of consciousness
We can understand thinking occuring without imagination or sensation [Descartes]
     Full Idea: We can understand thinking without imagination or sensation, as is quite clear to anyone who attends to the matter.
     From: René Descartes (Principles of Philosophy [1646], I.53)
     A reaction: We may certainly take it that Descartes means if it is understandable then it is logically possible. To believe that thinking could occur without imagination strikes me as an astonishing error. I take imagination to be more central than understanding.
16. Persons / D. Continuity of the Self / 7. Self and Thinking
In thinking we shut ourselves off from other substances, showing our identity and separateness [Descartes]
     Full Idea: Because each one of us understands what he thinks, and that in thinking he can shut himself off from every other substance, we may conclude that each of us is really distinct from every other thinking substance and from corporeal substance.
     From: René Descartes (Principles of Philosophy [1646], I.60)
     A reaction: This seems to be a novel argument which requires elucidation. I can 'shut myself off from every other substance'? If I shut myself off from thinking about food, does that mean hunger is not part of me? Or convince yourself that you don't have a brother?
16. Persons / F. Free Will / 1. Nature of Free Will
Our free will is so self-evident to us that it must be a basic innate idea [Descartes]
     Full Idea: It is so evident that we are possessed of a free will that can give or withhold its assent, that this may be counted as one of the first and most common notions found innately in us.
     From: René Descartes (Principles of Philosophy [1646], I.39)
     A reaction: It seems to me plausible to say that we have an innate conception of our own will (our ability to make decisions), though Hume says we only learn about the will from experience, but the idea that it is absolutely 'free' might never cross our minds.
17. Mind and Body / A. Mind-Body Dualism / 1. Dualism
There are two ultimate classes of existence: thinking substance and extended substance [Descartes]
     Full Idea: I observe two ultimate classes of things: intellectual or thinking things, pertaining to the mind or to thinking substance, and material things, pertaining to extended substance or to body.
     From: René Descartes (Principles of Philosophy [1646], I.48)
     A reaction: This is clear confirmation that Descartes believed the mind is a substance, rather than an insubstantial world of thinking. It leaves open the possibility of a different theory: that mind is not a substance, but is a Platonic adjunct to reality.
17. Mind and Body / D. Property Dualism / 5. Supervenience of mind
Even if tightly united, mind and body are different, as God could separate them [Descartes]
     Full Idea: Even if we suppose God had united a body and a soul so closely that they couldn't be closer, and made a single thing out of the two, they would still remain distinct, because God has the power of separating them, or conserving out without the other.
     From: René Descartes (Principles of Philosophy [1646], I.60)
     A reaction: If Descartes lost his belief in God (after discussing existence with Kant) would he cease to be a dualist? This quotation seems to be close to conceding a mind-body relationship more like supervenience than interaction.
18. Thought / A. Modes of Thought / 3. Emotions / g. Controlling emotions
Plato wanted to somehow control and purify the passions [Vlastos on Plato]
     Full Idea: Plato put high on his agenda a project which did not figure in Socrates' programme at all: the hygienic conditioning of the passions. This cannot be an intellectual process, as argument cannot touch them.
     From: comment on Plato (works [c.375 BCE]) by Gregory Vlastos - Socrates: Ironist and Moral Philosopher p.88
     A reaction: This is the standard traditional view of any thinker who exaggerates the importance and potential of reason in our lives.
18. Thought / A. Modes of Thought / 6. Judgement / b. Error
Most errors of judgement result from an inaccurate perception of the facts [Descartes]
     Full Idea: What usually misleads us is that we very frequently form a judgement although we do not have an accurate perception of what we judge.
     From: René Descartes (Principles of Philosophy [1646], I.33)
     A reaction: This seems to me a generally accurate observation, particularly in the making of moral judgements (which was probably not what Descartes was considering). The implication is that judgements are to a large extent forced by our perceptions.
19. Language / F. Communication / 1. Rhetoric
Plato's whole philosophy may be based on being duped by reification - a figure of speech [Benardete,JA on Plato]
     Full Idea: Plato is liable to the charge of having been duped by a figure of speech, albeit the most profound of all, the trope of reification.
     From: comment on Plato (works [c.375 BCE]) by José A. Benardete - Metaphysics: the logical approach Ch.12
     A reaction: That might be a plausible account if his view was ridiculous, but given how many powerful friends Plato has, especially in the philosophy of mathematics, we should assume he was cleverer than that.
20. Action / C. Motives for Action / 4. Responsibility for Actions
We do not praise the acts of an efficient automaton, as their acts are necessary [Descartes]
     Full Idea: We do not praise automata, although they respond exactly to the movements they were designed to produce, since their actions are performed necessarily
     From: René Descartes (Principles of Philosophy [1646], I.37)
     A reaction: I say we attribute responsibility when we perceive something like a 'person' as causing them. We don't blame small animals, because there is 'no one at home', but we blame children as they develop a full character and identity. We can ignore free will.
The greatest perfection of man is to act by free will, and thus merit praise or blame [Descartes]
     Full Idea: That the will should extend widely accords with its nature, and it is the greatest perfection in man to be able to act by its means, that is, freely, and by so doing we are in peculiar way masters of our actions, and thereby merit praise or blame.
     From: René Descartes (Principles of Philosophy [1646], I.37)
     A reaction: This seems to me to be a deep-rooted and false understanding which philosophy has inherited from theology. It doesn't strike me that there must an absolute 'buck-stop' to make us responsible. Why is it better for a decision to appear out of nowhere?
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / c. Ethical intuitionism
Plato never refers to examining the conscience [Plato, by Foucault]
     Full Idea: Plato never speaks of the examination of conscience - never!
     From: report of Plato (works [c.375 BCE]) by Michel Foucault - On the Genealogy of Ethics p.276
     A reaction: Plato does imply some sort of self-evident direct knowledge about that nature of a healthy soul. Presumably the full-blown concept of conscience is something given from outside, from God. In 'Euthyphro', Plato asserts the primacy of morality (Idea 337).
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
As religion and convention collapsed, Plato sought morals not just in knowledge, but in the soul [Williams,B on Plato]
     Full Idea: Once gods and fate and social expectation were no longer there, Plato felt it necessary to discover ethics inside human nature, not just as ethical knowledge (Socrates' view), but in the structure of the soul.
     From: comment on Plato (works [c.375 BCE]) by Bernard Williams - Shame and Necessity II - p.43
     A reaction: anti Charles Taylor
22. Metaethics / C. The Good / 1. Goodness / b. Types of good
Plato's legacy to European thought was the Good, the Beautiful and the True [Plato, by Gray]
     Full Idea: Plato's legacy to European thought was a trio of capital letters - the Good, the Beautiful and the True.
     From: report of Plato (works [c.375 BCE]) by John Gray - Straw Dogs 2.8
     A reaction: It seems to have been Baumgarten who turned this into a slogan (Idea 8117). Gray says these ideals are lethal, but I identify with them very strongly, and am quite happy to see the good life as an attempt to find the right balance between them.
22. Metaethics / C. The Good / 1. Goodness / f. Good as pleasure
Pleasure is better with the addition of intelligence, so pleasure is not the good [Plato, by Aristotle]
     Full Idea: Plato says the life of pleasure is more desirable with the addition of intelligence, and if the combination is better, pleasure is not the good.
     From: report of Plato (works [c.375 BCE]) by Aristotle - Nicomachean Ethics 1172b27
     A reaction: It is obvious why we like pleasure, but not why intelligence makes it 'better'. Maybe it is just because we enjoy intelligence?
22. Metaethics / C. The Good / 2. Happiness / d. Routes to happiness
Plato decided that the virtuous and happy life was the philosophical life [Plato, by Nehamas]
     Full Idea: Plato came to the conclusion that virtue and happiness consist in the life of philosophy itself.
     From: report of Plato (works [c.375 BCE]) by Alexander Nehamas - Eristic,Antilogic,Sophistic,Dialectic p.117
     A reaction: This view is obviously ridiculous, because it largely excludes almost the entire human race, which sees philosophy as a cul-de-sac, even if it is good. But virtue and happiness need some serious thought.
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
Plato, unusually, said that theoretical and practical wisdom are inseparable [Plato, by Kraut]
     Full Idea: Two virtues that are ordinarily kept distinct - theoretical and practical wisdom - are joined by Plato; he thinks that neither one can be fully possessed unless it is combined with the other.
     From: report of Plato (works [c.375 BCE]) by Richard Kraut - Plato
     A reaction: I get the impression that this doctrine comes from Socrates, whose position is widely reported as 'intellectualist'. Aristotle certainly held the opposite view.
23. Ethics / F. Existentialism / 4. Boredom
Plato is boring [Nietzsche on Plato]
     Full Idea: Plato is boring.
     From: comment on Plato (works [c.375 BCE]) by Friedrich Nietzsche - Twilight of the Idols 9.2
26. Natural Theory / A. Speculations on Nature / 1. Nature
Physics only needs geometry or abstract mathematics, which can explain and demonstrate everything [Descartes]
     Full Idea: I do not accept or desire any other principle in physics than in geometry or abstract mathematics, because all the phenomena of nature may be explained by their means, and sure demonstrations can be given of them.
     From: René Descartes (Principles of Philosophy [1646], 2.64), quoted by Peter Alexander - Ideas, Qualities and Corpuscles 7
     A reaction: This is his famous and rather extreme view, which might be described as hyper-pythagoreanism (by adding geometry to numbers). It seems to leave out matter, forces and activity.
26. Natural Theory / A. Speculations on Nature / 2. Natural Purpose / c. Purpose denied
We will not try to understand natural or divine ends, or final causes [Descartes]
     Full Idea: We will not seek for the reason of natural things from the end which God or nature has set before him in their creation .
     From: René Descartes (Principles of Philosophy [1646], §28)
     A reaction: Teleology is more relevant to biology than to the other sciences, and it is hard to understand an eye without a notion of 'what it is for'. Planetary motion reveals nothing about purposes. If you demand a purpose, it becomes more baffling.
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / c. Matter as extension
Matter is not hard, heavy or coloured, but merely extended in space [Descartes]
     Full Idea: The nature of matter, or body viewed as a whole, consists not in its being something which is hard, heavy, or colored, or which in any other way affects the senses, but only in its being a thing extended in length, breadth and depth.
     From: René Descartes (Principles of Philosophy [1646], 2.4), quoted by Robert Pasnau - Metaphysical Themes 1274-1671 04.5
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
We only see points in motion, and thereby infer movement [Rescher]
     Full Idea: We perceive motion only as isolated points, and then infer it without actually seeing it.
     From: Nicholas Rescher (Scepticism [1980], §112)
     A reaction: Note how writing suddenly becomes readable as you slow down on entering a railway station. Is that points suddenly becoming unified? This is an empiricist endorsement of Russell's 'at-at' account of motion.
27. Natural Reality / D. Time / 3. Parts of Time / a. Beginning of time
Almost everyone except Plato thinks that time could not have been generated [Plato, by Aristotle]
     Full Idea: With a single exception (Plato) everyone agrees about time - that it is not generated. Democritus says time is an obvious example of something not generated.
     From: report of Plato (works [c.375 BCE]) by Aristotle - Physics 251b14