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All the ideas for 'fragments/reports', 'What Required for Foundation for Maths?' and 'World and Essence'

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64 ideas

2. Reason / D. Definition / 2. Aims of Definition
Definitions make our intuitions mathematically useful [Mayberry]
     Full Idea: Definition provides us with the means for converting our intuitions into mathematically usable concepts.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-1)
2. Reason / E. Argument / 6. Conclusive Proof
Proof shows that it is true, but also why it must be true [Mayberry]
     Full Idea: When you have proved something you know not only that it is true, but why it must be true.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-2)
     A reaction: Note the word 'must'. Presumably both the grounding and the necessitation of the truth are revealed.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
Set theory can't be axiomatic, because it is needed to express the very notion of axiomatisation [Mayberry]
     Full Idea: Set theory cannot be an axiomatic theory, because the very notion of an axiomatic theory makes no sense without it.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.413-2)
     A reaction: This will come as a surprise to Penelope Maddy, who battles with ways to accept the set theory axioms as the foundation of mathematics. Mayberry says that the basic set theory required is much more simple and intuitive.
There is a semi-categorical axiomatisation of set-theory [Mayberry]
     Full Idea: We can give a semi-categorical axiomatisation of set-theory (all that remains undetermined is the size of the set of urelements and the length of the sequence of ordinals). The system is second-order in formalisation.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.413-2)
     A reaction: I gather this means the models may not be isomorphic to one another (because they differ in size), but can be shown to isomorphic to some third ingredient. I think. Mayberry says this shows there is no such thing as non-Cantorian set theory.
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
The misnamed Axiom of Infinity says the natural numbers are finite in size [Mayberry]
     Full Idea: The (misnamed!) Axiom of Infinity expresses Cantor's fundamental assumption that the species of natural numbers is finite in size.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2)
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The set hierarchy doesn't rely on the dubious notion of 'generating' them [Mayberry]
     Full Idea: The idea of 'generating' sets is only a metaphor - the existence of the hierarchy is established without appealing to such dubious notions.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2)
     A reaction: Presumably there can be a 'dependence' or 'determination' relation which does not involve actual generation.
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of size is part of the very conception of a set [Mayberry]
     Full Idea: Our very notion of a set is that of an extensional plurality limited in size.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.415-2)
5. Theory of Logic / A. Overview of Logic / 2. History of Logic
The mainstream of modern logic sees it as a branch of mathematics [Mayberry]
     Full Idea: In the mainstream tradition of modern logic, beginning with Boole, Peirce and Schröder, descending through Löwenheim and Skolem to reach maturity with Tarski and his school ...saw logic as a branch of mathematics.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.410-1)
     A reaction: [The lesser tradition, of Frege and Russell, says mathematics is a branch of logic]. Mayberry says the Fregean tradition 'has almost died out'.
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
First-order logic only has its main theorems because it is so weak [Mayberry]
     Full Idea: First-order logic is very weak, but therein lies its strength. Its principle tools (Compactness, Completeness, Löwenheim-Skolem Theorems) can be established only because it is too weak to axiomatize either arithmetic or analysis.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.411-2)
     A reaction: He adds the proviso that this is 'unless we are dealing with structures on whose size we have placed an explicit, finite bound' (p.412-1).
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Only second-order logic can capture mathematical structure up to isomorphism [Mayberry]
     Full Idea: Second-order logic is a powerful tool of definition: by means of it alone we can capture mathematical structure up to isomorphism using simple axiom systems.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1)
5. Theory of Logic / G. Quantification / 2. Domain of Quantification
Big logic has one fixed domain, but standard logic has a domain for each interpretation [Mayberry]
     Full Idea: The 'logica magna' [of the Fregean tradition] has quantifiers ranging over a fixed domain, namely everything there is. In the Boolean tradition the domains differ from interpretation to interpretation.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.410-2)
     A reaction: Modal logic displays both approaches, with different systems for global and local domains.
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
No Löwenheim-Skolem logic can axiomatise real analysis [Mayberry]
     Full Idea: No logic which can axiomatize real analysis can have the Löwenheim-Skolem property.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1)
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
'Classificatory' axioms aim at revealing similarity in morphology of structures [Mayberry]
     Full Idea: The purpose of a 'classificatory' axiomatic theory is to single out an otherwise disparate species of structures by fixing certain features of morphology. ...The aim is to single out common features.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.406-2)
Axiomatiation relies on isomorphic structures being essentially the same [Mayberry]
     Full Idea: The central dogma of the axiomatic method is this: isomorphic structures are mathematically indistinguishable in their essential properties.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.406-2)
     A reaction: Hence it is not that we have to settle for the success of a system 'up to isomorphism', since that was the original aim. The structures must differ in their non-essential properties, or they would be the same system.
'Eliminatory' axioms get rid of traditional ideal and abstract objects [Mayberry]
     Full Idea: The purpose of what I am calling 'eliminatory' axiomatic theories is precisely to eliminate from mathematics those peculiar ideal and abstract objects that, on the traditional view, constitute its subject matter.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.407-1)
     A reaction: A very interesting idea. I have a natural antipathy to 'abstract objects', because they really mess up what could otherwise be a very tidy ontology. What he describes might be better called 'ignoring' axioms. The objects may 'exist', but who cares?
5. Theory of Logic / K. Features of Logics / 6. Compactness
No logic which can axiomatise arithmetic can be compact or complete [Mayberry]
     Full Idea: No logic which can axiomatise arithmetic can be compact or complete.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1)
     A reaction: I take this to be because there are new truths in the transfinite level (as well as the problem of incompleteness).
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / g. Real numbers
Real numbers can be eliminated, by axiom systems for complete ordered fields [Mayberry]
     Full Idea: We eliminate the real numbers by giving an axiomatic definition of the species of complete ordered fields. These axioms are categorical (mutually isomorphic), and thus are mathematically indistinguishable.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.408-2)
     A reaction: Hence my clever mathematical friend says that it is a terrible misunderstanding to think that mathematics is about numbers. Mayberry says the reals are one ordered field, but mathematics now studies all ordered fields together.
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / b. Quantity
Greek quantities were concrete, and ratio and proportion were their science [Mayberry]
     Full Idea: Quantities for Greeks were concrete things - lines, surfaces, solids, times, weights. At the centre of their science of quantity was the beautiful theory of ratio and proportion (...in which the notion of number does not appear!).
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.407-2)
     A reaction: [He credits Eudoxus, and cites Book V of Euclid]
Real numbers were invented, as objects, to simplify and generalise 'quantity' [Mayberry]
     Full Idea: The abstract objects of modern mathematics, the real numbers, were invented by the mathematicians of the seventeenth century in order to simplify and to generalize the Greek science of quantity.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.407-2)
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Cantor's infinite is an absolute, of all the sets or all the ordinal numbers [Mayberry]
     Full Idea: In Cantor's new vision, the infinite, the genuine infinite, does not disappear, but presents itself in the guise of the absolute, as manifested in the species of all sets or the species of all ordinal numbers.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2)
Cantor extended the finite (rather than 'taming the infinite') [Mayberry]
     Full Idea: We may describe Cantor's achievement by saying, not that he tamed the infinite, but that he extended the finite.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.414-2)
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
If proof and definition are central, then mathematics needs and possesses foundations [Mayberry]
     Full Idea: If we grant, as surely we must, the central importance of proof and definition, then we must also grant that mathematics not only needs, but in fact has, foundations.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-1)
The ultimate principles and concepts of mathematics are presumed, or grasped directly [Mayberry]
     Full Idea: The ultimate principles upon which mathematics rests are those to which mathematicians appeal without proof; and the primitive concepts of mathematics ...themselves are grasped directly, if grasped at all, without the mediation of definition.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-1)
     A reaction: This begs the question of whether the 'grasping' is purely a priori, or whether it derives from experience. I defend the latter, and Jenkins puts the case well.
Foundations need concepts, definition rules, premises, and proof rules [Mayberry]
     Full Idea: An account of the foundations of mathematics must specify four things: the primitive concepts for use in definitions, the rules governing definitions, the ultimate premises of proofs, and rules allowing advance from premises to conclusions.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.405-2)
Axiom theories can't give foundations for mathematics - that's using axioms to explain axioms [Mayberry]
     Full Idea: No axiomatic theory, formal or informal, of first or of higher order can logically play a foundational role in mathematics. ...It is obvious that you cannot use the axiomatic method to explain what the axiomatic method is.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.415-2)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
1st-order PA is only interesting because of results which use 2nd-order PA [Mayberry]
     Full Idea: The sole theoretical interest of first-order Peano arithmetic derives from the fact that it is a first-order reduct of a categorical second-order theory. Its axioms can be proved incomplete only because the second-order theory is categorical.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1)
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
It is only 2nd-order isomorphism which suggested first-order PA completeness [Mayberry]
     Full Idea: If we did not know that the second-order axioms characterise the natural numbers up to isomorphism, we should have no reason to suppose, a priori, that first-order Peano Arithmetic should be complete.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-1)
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Set theory is not just first-order ZF, because that is inadequate for mathematics [Mayberry]
     Full Idea: The idea that set theory must simply be identified with first-order Zermelo-Fraenkel is surprisingly widespread. ...The first-order axiomatic theory of sets is clearly inadequate as a foundation of mathematics.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.412-2)
     A reaction: [He is agreeing with a quotation from Skolem].
We don't translate mathematics into set theory, because it comes embodied in that way [Mayberry]
     Full Idea: One does not have to translate 'ordinary' mathematics into the Zermelo-Fraenkel system: ordinary mathematics comes embodied in that system.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.415-1)
     A reaction: Mayberry seems to be a particular fan of set theory as spelling out the underlying facts of mathematics, though it has to be second-order.
Set theory is not just another axiomatised part of mathematics [Mayberry]
     Full Idea: The fons et origo of all confusion is the view that set theory is just another axiomatic theory and the universe of sets just another mathematical structure. ...The universe of sets ...is the world that all mathematical structures inhabit.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.416-1)
7. Existence / A. Nature of Existence / 5. Reason for Existence
Nothing could come out of nothing, and existence could never completely cease [Empedocles]
     Full Idea: From what in no wise exists, it is impossible for anything to come into being; for Being to perish completely is incapable of fulfilment and unthinkable.
     From: Empedocles (fragments/reports [c.453 BCE], B012), quoted by Anon (Lyc) - On Melissus 975b1-4
7. Existence / B. Change in Existence / 1. Nature of Change
Empedocles says things are at rest, unless love unites them, or hatred splits them [Empedocles, by Aristotle]
     Full Idea: Empedocles claims that things are alternately changing and at rest - that they are changing whenever love is creating a unity out of plurality, or hatred is creating plurality out of unity, and they are at rest in the times in between.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Physics 250b26
     A reaction: I suppose one must say that this an example of Ruskin's 'pathetic fallacy' - reading human emotions into the cosmos. Being constructive little creatures, we think goodness leads to construction. I'm afraid Empedocles is just wrong.
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
Real numbers as abstracted objects are now treated as complete ordered fields [Mayberry]
     Full Idea: The abstractness of the old fashioned real numbers has been replaced by generality in the modern theory of complete ordered fields.
     From: John Mayberry (What Required for Foundation for Maths? [1994], p.408-2)
     A reaction: In philosophy, I'm increasingly thinking that we should talk much more of 'generality', and a great deal less about 'universals'. (By which I don't mean that redness is just the set of red things).
9. Objects / A. Existence of Objects / 4. Impossible objects
Plantinga proposes necessary existent essences as surrogates for the nonexistent things [Plantinga, by Stalnaker]
     Full Idea: Plantinga proposes surrogates for nonexistent things - individual essences that are themselves necessary existents and that correspond one-to-one with all the 'things' that might exist.
     From: report of Alvin Plantinga (World and Essence [1970]) by Robert C. Stalnaker - Mere Possibilities 1
     A reaction: There are an awful lot of competing concepts of essence flying around these days. This one seems to require some abstract 'third realm' (or worse) in which these essences can exist, awaiting the arrival of thinkers. Not for me.
9. Objects / A. Existence of Objects / 5. Individuation / a. Individuation
The 'identity criteria' of a name are a group of essential and established facts [Plantinga]
     Full Idea: What we might call 'identity criteria' associated with a name such as 'Aristotle' are what the users of the name regard as essential and established facts about him.
     From: Alvin Plantinga (World and Essence [1970], I)
     A reaction: The problem here is that identifying something is superficial, whereas essences run deep. Plantinga is, in fact, talking about Lockean 'nominal essence' (and seems unaware of the fact, and never mentions the Lockean real/nominal distinction).
9. Objects / A. Existence of Objects / 5. Individuation / d. Individuation by haecceity
'Being Socrates' and 'being identical with Socrates' characterise Socrates, so they are among his properties [Plantinga]
     Full Idea: Surely it is true of Socrates that he is Socrates and he is identical with Socrates. If these are true of him, then 'being Socrates' and 'being identical with Socrates' characterize him; they are among his properties or attributes.
     From: Alvin Plantinga (World and Essence [1970], II)
     A reaction: As far as I can see (if you insist on accepting self-identity as meaningful) the most you get here is that these are predicates that can attach to Socrates. If you identify predicates with properties you are in deep metaphysical trouble.
9. Objects / A. Existence of Objects / 6. Nihilism about Objects
There is no coming-to-be of anything, but only mixing and separating [Empedocles, by Aristotle]
     Full Idea: Empedocles says there is no coming-to-be of anything, but only a mingling and a divorce of what has been mingled.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314b08
     A reaction: Aristotle comments that this prevents Empedocleans from distinguishing between superficial alteration and fundamental change of identity. Presumably, though, that wouldn't bother them.
9. Objects / D. Essence of Objects / 2. Types of Essence
Does Socrates have essential properties, plus a unique essence (or 'haecceity') which entails them? [Plantinga]
     Full Idea: Does Socrates have, in addition to his essential properties, an 'essence' or 'haecceity' - a property essential to him that entails each of his essential properties and that nothing distinct from him has in the world?
     From: Alvin Plantinga (World and Essence [1970], II)
     A reaction: Plantinga says yes, and offers 'Socrateity' (borrowed from Boethius) as his candidate. This is a very odd use of the word 'essence'. I take an essence to be a complex set of fundamental properties. I am also puzzled by his use of the word 'entails'.
9. Objects / D. Essence of Objects / 9. Essence and Properties
Properties are 'trivially essential' if they are instantiated by every object in every possible world [Plantinga]
     Full Idea: Let us call properties that enjoy the distinction of being instantiated by every object in every possible world 'trivially essential properties'.
     From: Alvin Plantinga (World and Essence [1970], I)
     A reaction: These would appear to be trivially 'necessary' rather than 'essential'. This continual need for the qualifier 'trivial' shows that they are not talking about proper essences.
X is essentially P if it is P in every world, or in every X-world, or in the actual world (and not ¬P elsewhere) [Plantinga]
     Full Idea: Socrates has P essentially if he has P in every world, or has it in every world in which he exists, or - most plausible of all - has P in the actual world and has its complement [non-P] in no world.
     From: Alvin Plantinga (World and Essence [1970], Intro)
     A reaction: These strike me as mere necessary properties, which are not the same thing at all. Essences give rise to the other properties, but Plantinga offers nothing to do the job (and especially not 'Socrateity'!). Essences must explain, say I!
If a property is ever essential, can it only ever be an essential property? [Plantinga]
     Full Idea: Is it the case that any property had essentially by anything is had essentially by everything that has it?
     From: Alvin Plantinga (World and Essence [1970], III)
     A reaction: Plantinga says it is not true, but the only example he can give is Socrates having the property of 'being Socrates or Greek'. I take it to be universally false. There are not two types of property here. Properties sometimes play an essential role.
Essences are instantiated, and are what entails a thing's properties and lack of properties [Plantinga]
     Full Idea: E is an essence if and only if (a) 'has E essentially' is instantiated in some world or other, and (b) for any world W and property P, E entails 'has P in W' or 'does not have P in W'.
     From: Alvin Plantinga (World and Essence [1970], IV)
     A reaction: 'Entail' strikes me as a very odd word when you are talking about the structure of the physical world (or are we??). Why would a unique self-identity (his candidate for essence) do the necessary entailing?
9. Objects / E. Objects over Time / 10. Beginning of an Object
Substance is not created or destroyed in mortals, but there is only mixing and exchange [Empedocles]
     Full Idea: There is no creation of substance in any one of mortal existence, nor any end in execrable death, but only mixing and exchange of what has been mixed.
     From: Empedocles (fragments/reports [c.453 BCE], B008), quoted by Plutarch - 74: Reply to Colotes 1111f
     A reaction: also Aristotle 314b08
9. Objects / F. Identity among Objects / 5. Self-Identity
Does 'being identical with Socrates' name a property? I can think of no objections to it [Plantinga]
     Full Idea: Is there any reason to suppose that 'being identical with Socrates' names a property? Well, is there any reason to suppose that it does not? I cannot think of any, nor have I heard any that are at all impressive.
     From: Alvin Plantinga (World and Essence [1970], II)
     A reaction: Is there any reason to think that a planet somewhere is entirely under the control of white mice? Extraordinary. No wonder Plantinga believes in God and the Ontological Argument, as well as the existence of 'Socrateity' etc.
10. Modality / A. Necessity / 4. De re / De dicto modality
'De re' modality is as clear as 'de dicto' modality, because they are logically equivalent [Plantinga]
     Full Idea: The idea of modality 'de re' is no more (although no less) obscure that the idea of modality 'de dicto'; for I think we can see that any statement of the former type is logically equivalent to some statement of the latter.
     From: Alvin Plantinga (World and Essence [1970], Intro)
     A reaction: If two things are logically equivalent, that doesn't ensure that they are equally clear! Personally I am on the side of de re modality.
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
We can imagine being beetles or alligators, so it is possible we might have such bodies [Plantinga]
     Full Idea: We easily understand Kafka's story about the man who wakes up to discover that he now has the body of a beetle; and in fact the state of affairs depicted is entirely possible. I can imagine being an alligator, so Socrates could have had an alligator body.
     From: Alvin Plantinga (World and Essence [1970], III)
     A reaction: This really is going the whole hog with accepting whatever is conceivable as being possible. I take this to be shocking nonsense, and it greatly reduces Plantinga in my esteem, despite his displays of intelligence and erudition.
13. Knowledge Criteria / E. Relativism / 3. Subjectivism
One vision is produced by both eyes [Empedocles]
     Full Idea: One vision is produced by both eyes
     From: Empedocles (fragments/reports [c.453 BCE], B088), quoted by Strabo - works 8.364.3
17. Mind and Body / A. Mind-Body Dualism / 3. Panpsychism
Wisdom and thought are shared by all things [Empedocles]
     Full Idea: Wisdom and power of thought, know thou, are shared in by all things.
     From: Empedocles (fragments/reports [c.453 BCE]), quoted by Sextus Empiricus - Against the Logicians (two books) II.286
     A reaction: Sextus quotes this, saying that it is 'still more paradoxical', and that it explicitly includes plants. This may mean that Empedocles was not including inanimate matter.
18. Thought / A. Modes of Thought / 1. Thought
For Empedocles thinking is almost identical to perception [Empedocles, by Theophrastus]
     Full Idea: Empedocles assumes that thinking is either identical to or very similar to sense-perception.
     From: report of Empedocles (fragments/reports [c.453 BCE], A86) by Theophrastus - On the Senses 9
     A reaction: Not to be sniffed at. We can, of course, control our thinking (though we can't control the controller) and we contemplate abstractions, but that might be seen as a sort of perception. Vision is not as visual as we think.
22. Metaethics / B. Value / 2. Values / j. Evil
Empedocles said good and evil were the basic principles [Empedocles, by Aristotle]
     Full Idea: Empedocles was the first to give evil and good as principles.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Metaphysics 985a
     A reaction: Once you start to think that good and evil will only matter if they have causal powers, it is an easy step to the idea of a benevolent god, and a satanic anti-god. Otherwise the 'principles' could be ignored.
26. Natural Theory / A. Speculations on Nature / 1. Nature
'Nature' is just a word invented by people [Empedocles]
     Full Idea: Nature is but a word of human framing.
     From: Empedocles (fragments/reports [c.453 BCE], B008), quoted by Aristotle - Metaphysics 1015a
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / e. The One
The principle of 'Friendship' in Empedocles is the One, and is bodiless [Empedocles, by Plotinus]
     Full Idea: In Empedocles we have a dividing principle, 'Strife', set against 'Friendship' - which is the One and is to him bodiless, while the elements represent matter.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Plotinus - The Enneads 5.1.09
     A reaction: The first time I've seen the principle of Love in Empedocles identified with the One of Parmenides. Plotinus is a trustworthy reporter, I think, because he was well read, and had access to lost texts.
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / f. Ancient elements
Empedocles said that there are four material elements, and two further creative elements [Empedocles, by Aristotle]
     Full Idea: Empedocles holds that the corporeal elements are four, but that all the elements, including those which create motion, are six in number.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314a16
Empedocles says bone is water, fire and earth in ratio 2:4:2 [Empedocles, by Inwood]
     Full Idea: Empedocles used numerical ratios to explain different kinds of matter; for example, bone is two parts water, four parts fire, two parts earth; and blood is an equal blend of all four elements.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Brad Inwood - Empedocles
     A reaction: Why isn't the ration 1:2:1? This presumably shows the influence of Pythagoras (who had also been based in Italy, like Empedocles), as well as that of the earlier naturalistic philosophers. It was a very good theory, though wrong.
Fire, Water, Air and Earth are elements, being simple as well as homoeomerous [Empedocles, by Aristotle]
     Full Idea: Empedocles says that Fire, Water, Air and Earth are four elements, and are thus 'simple' rather than flesh, bone and bodies which, like these, are 'homoeomeries'.
     From: report of Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 314a26
     A reaction: The translation is not quite clear. I take it that flesh and bone may look simple, because they are homoeomerous, but they are not really - but what is his evidence for that? Compare Idea 13208.
All change is unity through love or division through hate [Empedocles]
     Full Idea: These elements never cease their continuous exchange, sometimes uniting under the influence of Love, so that all become One, at other times again moving apart through the hostile force of Hate.
     From: Empedocles (fragments/reports [c.453 BCE], B017), quoted by Simplicius - On Aristotle's 'Physics' 158.1-
The elements combine in coming-to-be, but how do the elements themselves come-to-be? [Aristotle on Empedocles]
     Full Idea: Empedocles says it is evident that all the other bodies down to the 'elements' have their coming-to-be and their passing-away: but it is not clear how the 'elements' themselves, severally in their aggregated masses, come-to-be and pass-away.
     From: comment on Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 325b20
     A reaction: Presumably the elements are like axioms - and are just given. How do electrons and quarks come-to-be?
Love and Strife only explain movement if their effects are distinctive [Aristotle on Empedocles]
     Full Idea: It is not an adequate explanation to say that 'Love and Strife set things moving', unless the very nature of Love is a movement of this kind and the very nature of Strife a movement of that kind.
     From: comment on Empedocles (fragments/reports [c.453 BCE]) by Aristotle - Coming-to-be and Passing-away (Gen/Corr) 333b23
     A reaction: I take this to be of interest for showing Aristotle's quest for explanations, and his unwillingness to be fobbed off with anything superficial. I take a task of philosophy to be to push explanations further than others wish to go.
If the one Being ever diminishes it would no longer exist, and what could ever increase it? [Empedocles]
     Full Idea: Besides these elements, nothing else comes into being, nor does anything cease. For if they had been perishing continuously, they would Be no more; and what could increase the Whole? And whence could it have come?
     From: Empedocles (fragments/reports [c.453 BCE], B017), quoted by Simplicius - On Aristotle's 'Physics' 158.1-
27. Natural Reality / G. Biology / 3. Evolution
Maybe bodies are designed by accident, and the creatures that don't work are destroyed [Empedocles, by Aristotle]
     Full Idea: Is it just an accident that teeth and other parts of the body seem to have some purpose, and creatures survive because they happen to be put together in a useful way? Everything else has been destroyed, as Empedocles says of his 'cow with human head'.
     From: report of Empedocles (fragments/reports [c.453 BCE], 61) by Aristotle - Physics 198b29
     A reaction: Good grief! Has no one ever noticed that Empedocles proposed the theory of evolution? It isn't quite natural selection, because we aren't told what does the 'destroying', but it is a little flash of genius that was quietly forgotten.
28. God / A. Divine Nature / 2. Divine Nature
God is a pure, solitary, and eternal sphere [Empedocles]
     Full Idea: God is equal in all directions to himself and altogether eternal, a rounded Sphere enjoying a circular solitude.
     From: Empedocles (fragments/reports [c.453 BCE], B028), quoted by John Stobaeus - Anthology 1.15.2
God is pure mind permeating the universe [Empedocles]
     Full Idea: God is mind, holy and ineffable, and only mind, which darts through the whole cosmos with its swift thought.
     From: Empedocles (fragments/reports [c.453 BCE], B134), quoted by Ammonius - On 'De Interpretatione' 4.5.249.6
28. God / A. Divine Nature / 4. Divine Contradictions
In Empedocles' theory God is ignorant because, unlike humans, he doesn't know one of the elements (strife) [Aristotle on Empedocles]
     Full Idea: It is a consequence of Empedocles' view that God is the most unintelligent thing, for he alone is ignorant of one of the elements, namely strife, whereas mortal creatures are familiar with them all.
     From: comment on Empedocles (fragments/reports [c.453 BCE]) by Aristotle - De Anima 410b08
29. Religion / A. Polytheistic Religion / 2. Greek Polytheism
It is wretched not to want to think clearly about the gods [Empedocles]
     Full Idea: Wretched is he who cares not for clear thinking about the gods.
     From: Empedocles (fragments/reports [c.453 BCE], B132), quoted by Clement - Miscellanies 5.140.5.1