Combining Texts

All the ideas for 'Through the Looking Glass', 'De Corpore (Elements, First Section)' and 'Introduction to the Philosophy of Mathematics'

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62 ideas

1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Definitions are the first step in philosophy [Hobbes]
2. Reason / D. Definition / 2. Aims of Definition
Definitions of things that are caused must express their manner of generation [Hobbes]
2. Reason / D. Definition / 5. Genus and Differentia
Definition is resolution of names into successive genera, and finally the difference [Hobbes]
2. Reason / D. Definition / 8. Impredicative Definition
A defined name should not appear in the definition [Hobbes]
2. Reason / F. Fallacies / 3. Question Begging
'Petitio principii' is reusing the idea to be defined, in disguised words [Hobbes]
4. Formal Logic / E. Nonclassical Logics / 2. Intuitionist Logic
Showing a disproof is impossible is not a proof, so don't eliminate double negation [Colyvan]
Rejecting double negation elimination undermines reductio proofs [Colyvan]
4. Formal Logic / G. Formal Mereology / 3. Axioms of Mereology
A part of a part is a part of a whole [Hobbes]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Excluded middle says P or not-P; bivalence says P is either true or false [Colyvan]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Löwenheim proved his result for a first-order sentence, and Skolem generalised it [Colyvan]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Axioms are 'categorical' if all of their models are isomorphic [Colyvan]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / e. Ordinal numbers
If we just say one, one, one, one, we don't know where we have got to [Hobbes]
Ordinal numbers represent order relations [Colyvan]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / a. The Infinite
Intuitionists only accept a few safe infinities [Colyvan]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / j. Infinite divisibility
Infinitesimals were sometimes zero, and sometimes close to zero [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Reducing real numbers to rationals suggested arithmetic as the foundation of maths [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / f. Mathematical induction
Transfinite induction moves from all cases, up to the limit ordinal [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Most mathematical proofs are using set theory, but without saying so [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Structuralism say only 'up to isomorphism' matters because that is all there is to it [Colyvan]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
If 'in re' structures relies on the world, does the world contain rich enough structures? [Colyvan]
7. Existence / A. Nature of Existence / 3. Being / e. Being and nothing
I only wish I had such eyes as to see Nobody! It's as much as I can do to see real people. [Carroll,L]
7. Existence / B. Change in Existence / 1. Nature of Change
Change is nothing but movement [Hobbes]
8. Modes of Existence / B. Properties / 8. Properties as Modes
Accidents are just modes of thinking about bodies [Hobbes]
8. Modes of Existence / B. Properties / 12. Denial of Properties
Accidents are not parts of bodies (like blood in a cloth); they have accidents as things have a size [Hobbes]
8. Modes of Existence / C. Powers and Dispositions / 3. Powers as Derived
The complete power of an event is just the aggregate of the qualities that produced it [Hobbes]
8. Modes of Existence / E. Nominalism / 1. Nominalism / b. Nominalism about universals
The only generalities or universals are names or signs [Hobbes]
9. Objects / A. Existence of Objects / 5. Individuation / c. Individuation by location
Bodies are independent of thought, and coincide with part of space [Hobbes]
If you separated two things in the same place, you would also separate the places [Hobbes]
If you separate the two places of one thing, you will also separate the thing [Hobbes]
9. Objects / B. Unity of Objects / 1. Unifying an Object / b. Unifying aggregates
If a whole body is moved, its parts must move with it [Hobbes]
9. Objects / C. Structure of Objects / 8. Parts of Objects / b. Sums of parts
A body is always the same, whether the parts are together or dispersed [Hobbes]
9. Objects / C. Structure of Objects / 8. Parts of Objects / c. Wholes from parts
To make a whole, parts needn't be put together, but can be united in the mind [Hobbes]
9. Objects / D. Essence of Objects / 5. Essence as Kind
Particulars contain universal things [Hobbes]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / b. Essence not necessities
Some accidental features are permanent, unless the object perishes [Hobbes]
9. Objects / D. Essence of Objects / 13. Nominal Essence
The feature which picks out or names a thing is usually called its 'essence' [Hobbes]
9. Objects / E. Objects over Time / 8. Continuity of Rivers
It is the same river if it has the same source, no matter what flows in it [Hobbes]
9. Objects / E. Objects over Time / 9. Ship of Theseus
Some individuate the ship by unity of matter, and others by unity of form [Hobbes]
If a new ship were made of the discarded planks, would two ships be numerically the same? [Hobbes]
9. Objects / F. Identity among Objects / 3. Relative Identity
As an infant, Socrates was not the same body, but he was the same human being [Hobbes]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Two bodies differ when (at some time) you can say something of one you can't say of the other [Hobbes]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / b. Conceivable but impossible
We can imagine a point swelling and contracting - but not how this could be done [Hobbes]
14. Science / C. Induction / 6. Bayes's Theorem
Probability supports Bayesianism better as degrees of belief than as ratios of frequencies [Colyvan]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
Mathematics can reveal structural similarities in diverse systems [Colyvan]
14. Science / D. Explanation / 2. Types of Explanation / f. Necessity in explanations
Mathematics can show why some surprising events have to occur [Colyvan]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
Science aims to show causes and generation of things [Hobbes]
14. Science / D. Explanation / 2. Types of Explanation / m. Explanation by proof
Proof by cases (by 'exhaustion') is said to be unexplanatory [Colyvan]
Reductio proofs do not seem to be very explanatory [Colyvan]
If inductive proofs hold because of the structure of natural numbers, they may explain theorems [Colyvan]
Can a proof that no one understands (of the four-colour theorem) really be a proof? [Colyvan]
15. Nature of Minds / C. Capacities of Minds / 2. Imagination
Imagination is just weakened sensation [Hobbes]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Mathematical generalisation is by extending a system, or by abstracting away from it [Colyvan]
15. Nature of Minds / C. Capacities of Minds / 10. Conatus/Striving
A 'conatus' is an initial motion, experienced by us as desire or aversion [Hobbes, by Arthur,R]
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
Sensation is merely internal motion of the sentient being [Hobbes]
18. Thought / A. Modes of Thought / 3. Emotions / e. Basic emotions
Apart from pleasure and pain, the only emotions are appetite and aversion [Hobbes]
18. Thought / B. Mechanics of Thought / 5. Mental Files
Words are not for communication, but as marks for remembering what we have learned [Hobbes]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / b. Prime matter
Prime matter is body considered with mere size and extension, and potential [Hobbes]
26. Natural Theory / C. Causation / 1. Causation
Acting on a body is either creating or destroying a property in it [Hobbes]
26. Natural Theory / C. Causation / 8. Particular Causation / c. Conditions of causation
An effect needs a sufficient and necessary cause [Hobbes]
26. Natural Theory / C. Causation / 9. General Causation / d. Causal necessity
A cause is the complete sum of the features which necessitate the effect [Hobbes]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
Motion is losing one place and acquiring another [Hobbes]
27. Natural Reality / A. Classical Physics / 1. Mechanics / c. Forces
'Force' is the quantity of movement imposed on something [Hobbes]
27. Natural Reality / D. Time / 2. Passage of Time / k. Temporal truths
Past times can't exist anywhere, apart from in our memories [Hobbes]