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All the ideas for 'Parmenides', 'The Origin of Forms and Qualities' and 'The Philosopher's Toolkit'

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64 ideas

2. Reason / A. Nature of Reason / 1. On Reason
When questions are doubtful we should concentrate not on objects but on ideas of the intellect [Plato]
     Full Idea: Doubtful questions should not be discussed in terms of visible objects or in relation to them, but only with reference to ideas conceived by the intellect.
     From: Plato (Parmenides [c.364 BCE], 135e)
2. Reason / B. Laws of Thought / 2. Sufficient Reason
The Principle of Sufficient Reason does not presuppose that all explanations will be causal explanations [Baggini /Fosl]
     Full Idea: The Principle of Sufficient Reason does not presuppose that all explanations will be causal explanations.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §3.28)
     A reaction: This sounds a reasonable note of caution, but doesn't carry much weight unless some type of non-causal reason can be envisaged. God's free will? Our free will? The laws of causation?
2. Reason / B. Laws of Thought / 3. Non-Contradiction
You cannot rationally deny the principle of non-contradiction, because all reasoning requires it [Baggini /Fosl]
     Full Idea: Anyone who denies the principle of non-contradiction simultaneously affirms it; it cannot be rationally criticised, because it is presupposed by all rationality.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.12)
     A reaction: Nietzsche certainly wasn't afraid to ask why we should reject something because it is a contradiction. The 'logic of personal advantage' might allow logical contradictions.
2. Reason / B. Laws of Thought / 5. Opposites
Opposites are as unlike as possible [Plato]
     Full Idea: Opposites are as unlike as possible.
     From: Plato (Parmenides [c.364 BCE], 159a)
2. Reason / C. Styles of Reason / 1. Dialectic
Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic [Hegel on Plato]
     Full Idea: Plato's 'Parmenides' is the greatest artistic achievement of the ancient dialectic.
     From: comment on Plato (Parmenides [c.364 BCE]) by Georg W.F.Hegel - Phenomenology of Spirit Pref 71
     A reaction: It is a long way from the analytic tradition of philosophy to be singling out a classic text for its 'artistic' achievement. Eventually we may even look back on, say, Kripke's 'Naming and Necessity' and see it in that light.
Dialectic aims at unified truth, unlike analysis, which divides into parts [Baggini /Fosl]
     Full Idea: Dialectic can be said to aim at wholeness or unity, while 'analytic' thinking divides that with which it deals into parts.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §2.03)
     A reaction: I don't accept this division (linked here to Hegel). I am a fan of analysis, as practised by Aristotle, but it is like dismantling an engine to identify and clean the parts, before reassembling it more efficiently.
2. Reason / D. Definition / 4. Real Definition
Essential definitions show the differences that discriminate things, and make them what they are [Boyle]
     Full Idea: Essential definitions are such as are taken from the essential differences of things, which constitute them in such a sort of natural bodies, and discriminate them from all those of any other sort.
     From: Robert Boyle (The Origin of Forms and Qualities [1666], p.41?), quoted by Peter Alexander - Ideas, Qualities and Corpuscles
     A reaction: I don't think this goes as far as the aim Aristotle had in definitions, which was more than merely to 'discriminate' each thing. A full definition explains the thing as well.
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
'Natural' systems of deduction are based on normal rational practice, rather than on axioms [Baggini /Fosl]
     Full Idea: A 'natural' system of deduction does not posit any axioms, but looks instead for its formulae to the practices of ordinary rationality.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.09)
     A reaction: Presumably there is some middle ground, where we attempt to infer the axioms of normal practice, and then build a strict system on them. We must be allowed to criticise 'normal' rationality, I hope.
In ideal circumstances, an axiom should be such that no rational agent could possibly object to its use [Baggini /Fosl]
     Full Idea: In ideal circumstances, an axiom should be such that no rational agent could possibly object to its use.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.09)
     A reaction: Yes, but the trouble is that all our notions of 'rational' (giving reasons, being consistent) break down when we look at unsupported axioms. In what sense is something rational if it is self-evident?
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
The principle of bivalence distorts reality, as when claiming that a person is or is not 'thin' [Baggini /Fosl]
     Full Idea: Forcing everything into the straightjacket of bivalence seriously distorts the world. The problem is most acute in the case of vague concepts, such as thinness. It is not straightforwardly true or false that a person is thin.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §3.03)
     A reaction: Can't argue with that. Can we divide all our concepts into either bivalent or vague? Presumably both propositions and concepts could be bivalent.
5. Theory of Logic / L. Paradox / 3. Antinomies
Plato found antinomies in ideas, Kant in space and time, and Bradley in relations [Plato, by Ryle]
     Full Idea: Plato (in 'Parmenides') shows that the theory that 'Eide' are substances, and Kant that space and time are substances, and Bradley that relations are substances, all lead to aninomies.
     From: report of Plato (Parmenides [c.364 BCE]) by Gilbert Ryle - Are there propositions? 'Objections'
Plato's 'Parmenides' is perhaps the best collection of antinomies ever made [Russell on Plato]
     Full Idea: Plato's 'Parmenides' is perhaps the best collection of antinomies ever made.
     From: comment on Plato (Parmenides [c.364 BCE]) by Bertrand Russell - The Principles of Mathematics §337
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / a. For mathematical platonism
One is, so numbers exist, so endless numbers exist, and each one must partake of being [Plato]
     Full Idea: If one is, there must also necessarily be number - Necessarily - But if there is number, there would be many, and an unlimited multitude of beings. ..So if all partakes of being, each part of number would also partake of it.
     From: Plato (Parmenides [c.364 BCE], 144a)
     A reaction: This seems to commit to numbers having being, then to too many numbers, and hence to too much being - but without backing down and wondering whether numbers had being after all. Aristotle disagreed.
7. Existence / A. Nature of Existence / 3. Being / c. Becoming
The one was and is and will be and was becoming and is becoming and will become [Plato]
     Full Idea: The one was and is and will be and was becoming and is becoming and will become.
     From: Plato (Parmenides [c.364 BCE], 155d)
7. Existence / A. Nature of Existence / 3. Being / f. Primary being
Plato's Parmenides has a three-part theory, of Primal One, a One-Many, and a One-and-Many [Plato, by Plotinus]
     Full Idea: The Platonic Parmenides is more exact [than Parmenides himself]; the distinction is made between the Primal One, a strictly pure Unity, and a secondary One which is a One-Many, and a third which is a One-and-Many.
     From: report of Plato (Parmenides [c.364 BCE]) by Plotinus - The Enneads 5.1.08
     A reaction: Plotinus approves of this three-part theory. Parmenides has the problem that the highest Being contains no movement. By placing the One outside Being you can give it powers which an existent thing cannot have. Cf the concept of God.
7. Existence / D. Theories of Reality / 3. Reality
Absolute ideas, such as the Good and the Beautiful, cannot be known by us [Plato]
     Full Idea: The absolute good and the beautiful and all which we conceive to be absolute ideas are unknown to us.
     From: Plato (Parmenides [c.364 BCE], 134c)
8. Modes of Existence / C. Powers and Dispositions / 1. Powers
Boyle attacked a contemporary belief that powers were occult things [Boyle, by Alexander,P]
     Full Idea: Boyle attacks an idea of powers, held by some modern schoolmen and chemists, that makes powers occult.
     From: report of Robert Boyle (The Origin of Forms and Qualities [1666]) by Peter Alexander - Ideas, Qualities and Corpuscles 03.3
     A reaction: [This involves Boyle's famous example of a key having the power to turn a lock] On p.86 Alexander says the 'occult' belief is in affinities, antipathies, attractions and repulsions. How did Boyle explain magnetism?
8. Modes of Existence / C. Powers and Dispositions / 6. Dispositions / a. Dispositions
In the 17th century, 'disposition' usually just means the spatial arrangement of parts [Boyle, by Pasnau]
     Full Idea: In Locke and Boyle, 'disposition' and its various cognates are standardly used to refer to the corpuscular structure of a body - the spatial arrangement of its parts - without reflecting any commitment to a dispositional property.
     From: report of Robert Boyle (The Origin of Forms and Qualities [1666]) by Robert Pasnau - Metaphysical Themes 1274-1671 23.2
     A reaction: Here as a warning against enthusiasts for dispositional properties misreadigmg 17th century texts to their supposed advantage. Pasnau says none of them believe in dispositional properties or real powers.
8. Modes of Existence / D. Universals / 2. Need for Universals
If you deny that each thing always stays the same, you destroy the possibility of discussion [Plato]
     Full Idea: If a person denies that the idea of each thing is always the same, he will utterly destroy the power of carrying on discussion.
     From: Plato (Parmenides [c.364 BCE], 135c)
You must always mean the same thing when you utter the same name [Plato]
     Full Idea: You must always mean the same thing when you utter the same name.
     From: Plato (Parmenides [c.364 BCE], 147d)
8. Modes of Existence / D. Universals / 6. Platonic Forms / a. Platonic Forms
It would be absurd to think there were abstract Forms for vile things like hair, mud and dirt [Plato]
     Full Idea: Are there abstract ideas for such things as hair, mud and dirt, which are particularly vile and worthless? That would be quite absurd.
     From: Plato (Parmenides [c.364 BCE], 130d)
The concept of a master includes the concept of a slave [Plato]
     Full Idea: Mastership in the abstract is mastership of slavery in the abstract.
     From: Plato (Parmenides [c.364 BCE], 133e)
If admirable things have Forms, maybe everything else does as well [Plato]
     Full Idea: It is troubling that if admirable things have abstract ideas, then perhaps everything else must have ideas as well.
     From: Plato (Parmenides [c.364 BCE], 130d)
If absolute ideas existed in us, they would cease to be absolute [Plato]
     Full Idea: None of the absolute ideas exists in us, because then it would no longer be absolute.
     From: Plato (Parmenides [c.364 BCE], 133c)
Greatness and smallness must exist, to be opposed to one another, and come into being in things [Plato]
     Full Idea: These two ideas, greatness and smallness, exist, do they not? For if they did not exist, they could not be opposites of one another, and could not come into being in things.
     From: Plato (Parmenides [c.364 BCE], 149e)
Plato moves from Forms to a theory of genera and principles in his later work [Plato, by Frede,M]
     Full Idea: It seems to me that Plato in the later dialogues, beginning with the second half of 'Parmenides', wants to substitute a theory of genera and theory of principles that constitute these genera for the earlier theory of forms.
     From: report of Plato (Parmenides [c.364 BCE]) by Michael Frede - Title, Unity, Authenticity of the 'Categories' V
     A reaction: My theory is that the later Plato came under the influence of the brilliant young Aristotle, and this idea is a symptom of it. The theory of 'principles' sounds like hylomorphism to me.
8. Modes of Existence / D. Universals / 6. Platonic Forms / b. Partaking
The whole idea of each Form must be found in each thing which participates in it [Plato]
     Full Idea: The whole idea of each form (of beauty, justice etc) must be found in each thing which participates in it.
     From: Plato (Parmenides [c.364 BCE], 131a)
If things partake of ideas, this implies either that everything thinks, or that everything actually is thought [Plato]
     Full Idea: If all things partake of ideas, must either everything be made of thoughts and everything thinks, or everything is thought, and so can't think?
     From: Plato (Parmenides [c.364 BCE], 132c)
Participation is not by means of similarity, so we are looking for some other method of participation [Plato]
     Full Idea: Participation is not by means of likeness, so we must seek some other method of participation.
     From: Plato (Parmenides [c.364 BCE], 133a)
Each idea is in all its participants at once, just as daytime is a unity but in many separate places at once [Plato]
     Full Idea: Just as day is in many places at once, but not separated from itself, so each idea might be in all its participants at once.
     From: Plato (Parmenides [c.364 BCE], 131b)
If things are made alike by participating in something, that thing will be the absolute idea [Plato]
     Full Idea: That by participation in which like things are made like, will be the absolute idea, will it not?
     From: Plato (Parmenides [c.364 BCE], 132e)
8. Modes of Existence / D. Universals / 6. Platonic Forms / c. Self-predication
Nothing can be like an absolute idea, because a third idea intervenes to make them alike (leading to a regress) [Plato]
     Full Idea: It is impossible for anything to be like an absolute idea, because a third idea will appear to make them alike, and if that is like anything, it will lead to another idea, and so on.
     From: Plato (Parmenides [c.364 BCE], 133a)
If absolute greatness and great things are seen as the same, another thing appears which makes them seem great [Plato]
     Full Idea: If you regard the absolute great and the many great things in the same way, will not another appear beyond, by which all these must appear to be great?
     From: Plato (Parmenides [c.364 BCE], 132a)
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
Parts must belong to a created thing with a distinct form [Plato]
     Full Idea: The part would not be the part of many things or all, but of some one character ['ideas'] and of some one thing, which we call a 'whole', since it has come to be one complete [perfected] thing composed [created] of all.
     From: Plato (Parmenides [c.364 BCE], 157d)
     A reaction: A serious shot by Plato at what identity is. Harte quotes it (125) and shows that 'character' is Gk 'idea', and 'composed' will translate as 'created'. 'Form' links this Platonic passage to Aristotle's hylomorphism.
9. Objects / C. Structure of Objects / 2. Hylomorphism / a. Hylomorphism
Form is not a separate substance, but just the manner, modification or 'stamp' of matter [Boyle]
     Full Idea: I understand the word 'form' to mean, not a real substance distinct from matter, but only the matter itself of a natural body, with its peculiar manner of existence [corpuscular structure], which may be called its 'essential modification' or 'stamp'.
     From: Robert Boyle (The Origin of Forms and Qualities [1666], p.324), quoted by Jan-Erik Jones - Real Essence §3
     A reaction: I don't think Aristotle ever thought that a form was separate from its matter, let alone qualifying as a substance. On the whole, Boyle attacks scholastic philosophy, rather than Aristotle.
To cite a substantial form tells us what produced the effect, but not how it did it [Boyle]
     Full Idea: If it be demanded why rhubarb purges choler, snow dazzles the eyes rather than grass etc., that these effects are performed by substantial forms of the respective bodies is at best but to tell me what is the agent, not how the effect is wrought.
     From: Robert Boyle (The Origin of Forms and Qualities [1666], p.47?), quoted by Peter Alexander - Ideas, Qualities and Corpuscles 01.2
     A reaction: This is the problem of the 'virtus dormitiva' of opium (which at least tells you it was the opium what done it). I take Aristotle to have aspired to a lot more than this. He wanted a full definition, which would contain lots of information about the form.
9. Objects / C. Structure of Objects / 5. Composition of an Object
In Parmenides, if composition is identity, a whole is nothing more than its parts [Plato, by Harte,V]
     Full Idea: At the heart of the 'Parmenides' puzzles about composition is the thesis that composition is identity. Considered thus, a whole adds nothing to an ontology that already includes its parts
     From: report of Plato (Parmenides [c.364 BCE]) by Verity Harte - Plato on Parts and Wholes 2.5
     A reaction: There has to be more to a unified identity that mere proximity of the parts. When do parts come together, and when do they actually 'compose' something?
9. Objects / C. Structure of Objects / 8. Parts of Objects / a. Parts of objects
Plato says only a one has parts, and a many does not [Plato, by Harte,V]
     Full Idea: In 'Parmenides' it is argued that a part cannot be part of a many, but must be part of something one.
     From: report of Plato (Parmenides [c.364 BCE], 157c) by Verity Harte - Plato on Parts and Wholes 3.2
     A reaction: This looks like the right way to go with the term 'part'. We presuppose a unity before we even talk of its parts, so we can't get into contradictions and paradoxes about their relationships.
Anything which has parts must be one thing, and parts are of a one, not of a many [Plato]
     Full Idea: The whole of which the parts are parts must be one thing composed of many; for each of the parts must be part, not of a many, but of a whole.
     From: Plato (Parmenides [c.364 BCE], 157c)
     A reaction: This is a key move of metaphysics, and we should hang on to it. The other way madness lies.
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
It seems that the One must be composed of parts, which contradicts its being one [Plato]
     Full Idea: The One must be composed of parts, both being a whole and having parts. So on both grounds the One would thus be many and not one. But it must be not many, but one. So if the One will be one, it will neither be a whole, nor have parts.
     From: Plato (Parmenides [c.364 BCE], 137c09), quoted by Kathrin Koslicki - The Structure of Objects 5.2
     A reaction: This is the starting point for Plato's metaphysical discussion of objects. It seems to begin a line of thought which is completed by Aristotle, surmising that only an essential structure can bestow identity on a bunch of parts.
9. Objects / F. Identity among Objects / 3. Relative Identity
If identity is based on 'true of X' instead of 'property of X' we get the Masked Man fallacy ('I know X but not Y') [Baggini /Fosl, by PG]
     Full Idea: The Masked Man fallacy is when Leibniz's Law is taken as 'X and Y are identical if what is true of X is true of Y' (rather than being about properties). Then 'I know X' but 'I don't know Y' (e.g. my friend wearing a mask) would make X and Y non-identical.
     From: report of J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §3.17) by PG - Db (ideas)
     A reaction: As the book goes on to explain, Descartes is guilty of this when arguing that I necessarily know my mind but not my body, so they are different. Seems to me that Kripke falls into the same trap.
9. Objects / F. Identity among Objects / 4. Type Identity
'I have the same car as you' is fine; 'I have the same fiancée as you' is not so good [Baggini /Fosl]
     Full Idea: If you found that I had the same car as you, I don't suppose you would care, but if you found I had the same fiancée as you, you might not be so happy.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §4.17)
     A reaction: A very nice illustration of the ambiguity of "same", and hence of identity. 'I had the same thought as you'. 'I have the same DNA as you'.
9. Objects / F. Identity among Objects / 6. Identity between Objects
Two things relate either as same or different, or part of a whole, or the whole of the part [Plato]
     Full Idea: Everything is surely related to everything as follows: either it is the same or different; or, if it is not the same or different, it would be related as part to whole or as whole to part.
     From: Plato (Parmenides [c.364 BCE], 146b)
     A reaction: This strikes me as a really helpful first step in trying to analyse the nature of identity. Two things are either two or (actually) one, or related mereologically.
9. Objects / F. Identity among Objects / 7. Indiscernible Objects
Leibniz's Law is about the properties of objects; the Identity of Indiscernibles is about perception of objects [Baggini /Fosl]
     Full Idea: Leibniz's Law ('if identical, must have same properties') defines identity according to the properties possessed by the object itself, but the Identity of Indiscernibles defines identity in terms of how things are conceived or grasped by the mind.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §3.16)
     A reaction: This is the heart of the problem of identity. We realists must fight for Leibniz's Law, and escort the Identity of Indiscernibles to the door.
10. Modality / A. Necessity / 3. Types of Necessity
Is 'events have causes' analytic a priori, synthetic a posteriori, or synthetic a priori? [Baggini /Fosl]
     Full Idea: Of the proposition that "all experienced events have causes", Descartes says this is analytic a priori, Hume says it is synthetic a posteriori, and Kant says it is synthetic a priori.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §4.01)
     A reaction: I am not sympathetic to Hume on this (though most people think he is right). I prefer the Kantian view, but he makes a very large claim. Something has to be intuitive.
12. Knowledge Sources / A. A Priori Knowledge / 1. Nature of the A Priori
'A priori' does not concern how you learn a proposition, but how you show whether it is true or false [Baggini /Fosl]
     Full Idea: What makes something a priori is not the means by which it came to be known, but the means by which it can be shown to be true or false.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §4.01)
     A reaction: Helpful. Kripke in particular has labelled the notion as an epistemological one, but that does imply a method of acquiring it. Clearly I can learn an a priori truth by reading it the newspaper.
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
Boyle's term 'texture' is not something you feel, but is unobservable structures of particles [Boyle, by Alexander,P]
     Full Idea: Perhaps Boyle's most important technical terms is 'texture'. ...It must not be confused with the way we feel the texture of a surface like sandpaper or velvet; it is rather a structure of unobservable particles and so it is not directly observable.
     From: report of Robert Boyle (The Origin of Forms and Qualities [1666]) by Peter Alexander - Ideas, Qualities and Corpuscles 03.2
     A reaction: This is the basis for Alexander's reassessment of what Boyle and Locke meant by a 'secondary quality', which, he says, is a physical feature of objects, not a mental experience.
Boyle's secondary qualities are not illusory, or 'in the mind' [Boyle, by Alexander,P]
     Full Idea: There is no suggestion in Boyle that secondary qualities are, unlike primary qualities, somehow illusory, subjective or 'in the mind'.
     From: report of Robert Boyle (The Origin of Forms and Qualities [1666]) by Peter Alexander - Ideas, Qualities and Corpuscles 03.3
     A reaction: [Alexander goes on to say that his also applied to Locke]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / b. Basic beliefs
Basic beliefs are self-evident, or sensual, or intuitive, or revealed, or guaranteed [Baggini /Fosl]
     Full Idea: Sentence are held to be basic because they are self-evident or 'cataleptic' (Stoics), or rooted in sense data (positivists), or grasped by intuition (Platonists), or revealed by God, or grasped by faculties certified by God (Descartes).
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.01)
     A reaction: These are a bit blurred. Isn't intuition self-evident? Isn't divine guarantee a type of revelation? How about reason, experience or authority?
14. Science / A. Basis of Science / 6. Falsification
A proposition such as 'some swans are purple' cannot be falsified, only verified [Baggini /Fosl]
     Full Idea: The problem with falsification is that it fails to work with logically particular claims such as 'some swans are purple'. Examining a million swans and finding no purple ones does not falsify the claim, as there might still be a purple swan out there.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §3.29)
     A reaction: Isn't it beautiful how unease about a theory (Popper's) slowly crystallises into an incredibly simple and devastating point? Maybe 'some swans are purple' isn't science unless there is a good reason to propose it?
14. Science / C. Induction / 1. Induction
The problem of induction is how to justify our belief in the uniformity of nature [Baggini /Fosl]
     Full Idea: At its simplest, the problem of induction can be boiled down to the problem of justifying our belief in the uniformity of nature.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.03)
     A reaction: An easy solution to the problem of induction: we treat the uniformity of nature as axiomatic, and then induction is all reasoning which is based on that axiom. The axiom is a working hypothesis, which may begin to appear false. Anomalies are hard.
14. Science / C. Induction / 4. Reason in Induction
How can an argument be good induction, but poor deduction? [Baggini /Fosl]
     Full Idea: The problem of induction is the problem of how an argument can be good reasoning as induction but poor reasoning as deduction.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.03)
     A reaction: Nicely put, and a good defence of Hume against the charge that he has just muddled induction and deduction. All reasoning, we insist, should be consistent, or it isn't reasoning.
14. Science / D. Explanation / 2. Types of Explanation / i. Explanations by mechanism
Explanation is deducing a phenomenon from some nature better known to us [Boyle]
     Full Idea: Explicating a phenomenon is to deduce it from something else in nature more known to us than the thing to be explained by it.
     From: Robert Boyle (The Origin of Forms and Qualities [1666], p.46?), quoted by Peter Alexander - Ideas, Qualities and Corpuscles
     A reaction: Interesting that the word 'deduce' is here, beloved of the 'covering law' view. But this may be deduced from the behaviour of other substances, as the iron filing behaviour may be explained by the magnet itself (or perhaps 'laws' of magnetism).
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
Abduction aims at simplicity, testability, coherence and comprehensiveness [Baggini /Fosl]
     Full Idea: There are some 'principles of selection' in abduction: 1) prefer simple explanations, 2) prefer coherent explanations (consistent with what is already held true), 3) prefer theories that make testable predictions, and 4) be comprehensive in scope.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §2.01)
     A reaction: Note that these are desirable, but not necessary (pace Ockham and Ayer). I cannot think of anything to add to the list, so I will adopt it. Abduction is the key to rationality.
To see if an explanation is the best, it is necessary to investigate the alternative explanations [Baggini /Fosl]
     Full Idea: The only way to be sure we have the best explanation is to investigate the alternatives and see if they are any better.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §3.01)
     A reaction: Unavoidable! Since I love 'best explanation', I now seem to be committed to investigation every mad theory that comes up, just in case it is better. I hope I am allowed to reject after a very quick sniff.
18. Thought / A. Modes of Thought / 5. Rationality / a. Rationality
Consistency is the cornerstone of rationality [Baggini /Fosl]
     Full Idea: Consistency is the cornerstone of rationality.
     From: J Baggini / PS Fosl (The Philosopher's Toolkit [2003], §1.06)
     A reaction: This is right, and is a cornerstone of Kant's approach to ethics. Rational beings must follow principles - in order to be consistent in their behaviour. 'Consistent' now requires a definition….
25. Social Practice / E. Policies / 5. Education / c. Teaching
Only a great person can understand the essence of things, and an even greater person can teach it [Plato]
     Full Idea: Only a man of very great natural gifts will be able to understand that everything has a class and absolute essence, and an even more wonderful man can teach this.
     From: Plato (Parmenides [c.364 BCE], 135a)
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / d. The unlimited
The unlimited has no shape and is endless [Plato]
     Full Idea: The unlimited partakes neither of the round nor of the straight, because it has no ends nor edges.
     From: Plato (Parmenides [c.364 BCE], 137e)
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / e. The One
Some things do not partake of the One [Plato]
     Full Idea: The others cannot partake of the one in any way; they can neither partake of it nor of the whole.
     From: Plato (Parmenides [c.364 BCE], 159d)
     A reaction: Compare Idea 231
The only movement possible for the One is in space or in alteration [Plato]
     Full Idea: If the One moves it either moves spatially or it is altered, since these are the only motions.
     From: Plato (Parmenides [c.364 BCE], 138b)
Everything partakes of the One in some way [Plato]
     Full Idea: The others are not altogether deprived of the one, for they partake of it in some way.
     From: Plato (Parmenides [c.364 BCE], 157c)
     A reaction: Compare Idea 233.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
The corpuscles just have shape, size and motion, which explains things without 'sympathies' or 'forces' [Boyle, by Alexander,P]
     Full Idea: In Boyle's corpuscular philosophy, all material substances are composed of minute particles or corpuscles, with ordinary properties such as shape, size and motion. There was no need for occult relations between them, such as sympathies, or even forces.
     From: report of Robert Boyle (The Origin of Forms and Qualities [1666]) by Peter Alexander - Ideas, Qualities and Corpuscles 01.1
26. Natural Theory / A. Speculations on Nature / 7. Later Matter Theories / b. Corpuscles
The corpuscular theory allows motion, but does not include forces between the particles [Boyle, by Alexander,P]
     Full Idea: Though there is motion, the corpuscles will not be dynamic because the idea of forces between the particles or groups of them does not figure in the theory.
     From: report of Robert Boyle (The Origin of Forms and Qualities [1666]) by Peter Alexander - Ideas, Qualities and Corpuscles 5.2
     A reaction: This is the view of Locke, as well as of Boyle. I quote this because I take to it be a particular target of Leibniz's disagreement.
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
We couldn't discuss the non-existence of the One without knowledge of it [Plato]
     Full Idea: There must be knowledge of the one, or else not even the meaning of the words 'if the one does not exist' would be known.
     From: Plato (Parmenides [c.364 BCE], 160d)