Combining Texts

All the ideas for 'Thinking About Mathematics', 'The Logic of What Might Have Been' and 'Reasoning and the Logic of Things'

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82 ideas

1. Philosophy / D. Nature of Philosophy / 2. Invocation to Philosophy
Everything interesting should be recorded, with records that can be rearranged [Peirce]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / a. Philosophy as worldly
Sciences concern existence, but philosophy also concerns potential existence [Peirce]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
An idea on its own isn't an idea, because they are continuous systems [Peirce]
1. Philosophy / D. Nature of Philosophy / 6. Hopes for Philosophy
Philosophy is a search for real truth [Peirce]
1. Philosophy / E. Nature of Metaphysics / 1. Nature of Metaphysics
Metaphysics is pointless without exact modern logic [Peirce]
1. Philosophy / E. Nature of Metaphysics / 5. Metaphysics beyond Science
Metaphysics is the science of both experience, and its general laws and types [Peirce]
1. Philosophy / E. Nature of Metaphysics / 6. Metaphysics as Conceptual
Metaphysical reasoning is simple enough, but the concepts are very hard [Peirce]
1. Philosophy / F. Analytic Philosophy / 6. Logical Analysis
Metaphysics is turning into logic, and logic is becoming mathematics [Peirce]
3. Truth / A. Truth Problems / 6. Verisimilitude
The one unpardonable offence in reasoning is to block the route to further truth [Peirce]
3. Truth / E. Pragmatic Truth / 1. Pragmatic Truth
'Holding for true' is either practical commitment, or provisional theory [Peirce]
4. Formal Logic / D. Modal Logic ML / 2. Tools of Modal Logic / b. Terminology of ML
A world is 'accessible' to another iff the first is possible according to the second [Salmon,N]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / d. System T
For metaphysics, T may be the only correct system of modal logic [Salmon,N]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / f. System B
System B has not been justified as fallacy-free for reasoning on what might have been [Salmon,N]
In B it seems logically possible to have both p true and p is necessarily possibly false [Salmon,N]
System B implies that possibly-being-realized is an essential property of the world [Salmon,N]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / g. System S4
What is necessary is not always necessarily necessary, so S4 is fallacious [Salmon,N]
4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
S5 modal logic ignores accessibility altogether [Salmon,N]
S5 believers say that-things-might-have-been-that-way is essential to ways things might have been [Salmon,N]
The unsatisfactory counterpart-theory allows the retention of S5 [Salmon,N]
4. Formal Logic / D. Modal Logic ML / 4. Alethic Modal Logic
Metaphysical (alethic) modal logic concerns simple necessity and possibility (not physical, epistemic..) [Salmon,N]
5. Theory of Logic / B. Logical Consequence / 4. Semantic Consequence |=
Deduction is true when the premises facts necessarily make the conclusion fact true [Peirce]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
Our research always hopes that reality embodies the logic we are employing [Peirce]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Intuitionists deny excluded middle, because it is committed to transcendent truth or objects [Shapiro]
5. Theory of Logic / E. Structures of Logic / 6. Relations in Logic
The logic of relatives relies on objects built of any relations (rather than on classes) [Peirce]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
The number 3 is presumably identical as a natural, an integer, a rational, a real, and complex [Shapiro]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / h. Reals from Cauchy
Cauchy gave a formal definition of a converging sequence. [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 1. Foundations for Mathematics
Categories are the best foundation for mathematics [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / f. Zermelo numbers
Two definitions of 3 in terms of sets disagree over whether 1 is a member of 3 [Shapiro]
6. Mathematics / B. Foundations for Mathematics / 7. Mathematical Structuralism / a. Structuralism
Numbers do not exist independently; the essence of a number is its relations to other numbers [Shapiro]
A 'system' is related objects; a 'pattern' or 'structure' abstracts the pure relations from them [Shapiro]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Logicism seems to be a non-starter if (as is widely held) logic has no ontology of its own [Shapiro]
6. Mathematics / C. Sources of Mathematics / 7. Formalism
Term Formalism says mathematics is just about symbols - but real numbers have no names [Shapiro]
Game Formalism is just a matter of rules, like chess - but then why is it useful in science? [Shapiro]
Deductivism says mathematics is logical consequences of uninterpreted axioms [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / b. Intuitionism
Critics resent the way intuitionism cripples mathematics, but it allows new important distinctions [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / c. Conceptualism
We now know that mathematics only studies hypotheses, not facts [Peirce]
Conceptualist are just realists or idealist or nominalists, depending on their view of concepts [Shapiro]
6. Mathematics / C. Sources of Mathematics / 10. Constructivism / d. Predicativism
'Impredicative' definitions refer to the thing being described [Shapiro]
7. Existence / D. Theories of Reality / 2. Realism
Realism is the belief that there is something in the being of things corresponding to our reasoning [Peirce]
There may be no reality; it's just our one desperate hope of knowing anything [Peirce]
9. Objects / D. Essence of Objects / 15. Against Essentialism
Any property is attached to anything in some possible world, so I am a radical anti-essentialist [Salmon,N]
10. Modality / A. Necessity / 3. Types of Necessity
Logical possibility contains metaphysical possibility, which contains nomological possibility [Salmon,N]
10. Modality / A. Necessity / 5. Metaphysical Necessity
Metaphysical necessity is said to be unrestricted necessity, true in every world whatsoever [Salmon,N]
Bizarre identities are logically but not metaphysically possible, so metaphysical modality is restricted [Salmon,N]
Metaphysical necessity is NOT truth in all (unrestricted) worlds; necessity comes first, and is restricted [Salmon,N]
Without impossible worlds, the unrestricted modality that is metaphysical has S5 logic [Salmon,N]
In the S5 account, nested modalities may be unseen, but they are still there [Salmon,N]
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity is free of constraints, and may accommodate all of S5 logic [Salmon,N]
10. Modality / A. Necessity / 7. Natural Necessity
Nomological necessity is expressed with intransitive relations in modal semantics [Salmon,N]
10. Modality / B. Possibility / 7. Chance
Objective chance is the property of a distribution [Peirce]
10. Modality / B. Possibility / 8. Conditionals / e. Supposition conditionals
In ordinary language a conditional statement assumes that the antecedent is true [Peirce]
10. Modality / C. Sources of Modality / 5. Modality from Actuality
Necessity and possibility are not just necessity and possibility according to the actual world [Salmon,N]
10. Modality / E. Possible worlds / 1. Possible Worlds / b. Impossible worlds
Impossible worlds are also ways for things to be [Salmon,N]
Denial of impossible worlds involves two different confusions [Salmon,N]
Without impossible worlds, how things might have been is the only way for things to be [Salmon,N]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
Possible worlds rely on what might have been, so they can' be used to define or analyse modality [Salmon,N]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Possible worlds are maximal abstract ways that things might have been [Salmon,N]
Possible worlds just have to be 'maximal', but they don't have to be consistent [Salmon,N]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / c. Worlds as propositions
You can't define worlds as sets of propositions, and then define propositions using worlds [Salmon,N]
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
We act on 'full belief' in a crisis, but 'opinion' only operates for trivial actions [Peirce]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
12. Knowledge Sources / D. Empiricism / 2. Associationism
We talk of 'association by resemblance' but that is wrong: the association constitutes the resemblance [Peirce]
13. Knowledge Criteria / B. Internal Justification / 3. Evidentialism / a. Evidence
Scientists will give up any conclusion, if experience opposes it [Peirce]
14. Science / A. Basis of Science / 2. Demonstration
If each inference slightly reduced our certainty, science would soon be in trouble [Peirce]
14. Science / B. Scientific Theories / 1. Scientific Theory
I classify science by level of abstraction; principles derive from above, and data from below [Peirce]
14. Science / C. Induction / 2. Aims of Induction
'Induction' doesn't capture Greek 'epagoge', which is singulars in a mass producing the general [Peirce]
14. Science / C. Induction / 3. Limits of Induction
How does induction get started? [Peirce]
Induction can never prove that laws have no exceptions [Peirce]
The worst fallacy in induction is generalising one recondite property from a sample [Peirce]
14. Science / D. Explanation / 4. Explanation Doubts / b. Rejecting explanation
Men often answer inner 'whys' by treating unconscious instincts as if they were reasons [Peirce]
15. Nature of Minds / A. Nature of Mind / 7. Animal Minds
We may think animals reason very little, but they hardly ever make mistakes! [Peirce]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Generalisation is the great law of mind [Peirce]
Generalization is the true end of life [Peirce]
16. Persons / C. Self-Awareness / 2. Knowing the Self
'Know yourself' is not introspection; it is grasping how others see you [Peirce]
17. Mind and Body / A. Mind-Body Dualism / 3. Panpsychism
Whatever is First must be sentient [Peirce]
18. Thought / A. Modes of Thought / 5. Rationality / a. Rationality
Reasoning involves observation, experiment, and habituation [Peirce]
18. Thought / A. Modes of Thought / 5. Rationality / b. Human rationality
Everybody overrates their own reasoning, so it is clearly superficial [Peirce]
19. Language / C. Assigning Meanings / 9. Indexical Semantics
Indexicals are unusual words, because they stimulate the hearer to look around [Peirce]
23. Ethics / D. Deontological Ethics / 2. Duty
People should follow what lies before them, and is within their power [Peirce]
25. Social Practice / E. Policies / 5. Education / b. Education principles
We are not inspired by other people's knowledge; a sense of our ignorance motivates study [Peirce]
26. Natural Theory / B. Natural Kinds / 1. Natural Kinds
Chemists rely on a single experiment to establish a fact; repetition is pointless [Peirce]
26. Natural Theory / D. Laws of Nature / 1. Laws of Nature
Our laws of nature may be the result of evolution [Peirce]