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All the ideas for 'On the Question of Absolute Undecidability', 'Tractatus Logico-Philosophicus' and 'Posterior Analytics'

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178 ideas

1. Philosophy / D. Nature of Philosophy / 1. Philosophy
What we cannot speak about we must pass over in silence [Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
I say (contrary to Wittgenstein) that philosophy expresses what we thought we must be silent about [Ansell Pearson on Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 6. Hopes for Philosophy
If a question can be framed at all, it is also possible to answer it [Wittgenstein]
1. Philosophy / D. Nature of Philosophy / 7. Despair over Philosophy
The 'Tractatus' is a masterpiece of anti-philosophy [Badiou on Wittgenstein]
This work solves all the main problems, but that has little value [Wittgenstein]
Once you understand my book you will see that it is nonsensical [Wittgenstein]
1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
The limits of my language means the limits of my world [Wittgenstein]
All complex statements can be resolved into constituents and descriptions [Wittgenstein]
Our language is an aspect of biology, and so its inner logic is opaque [Wittgenstein]
Most philosophical questions arise from failing to understand the logic of language [Wittgenstein]
1. Philosophy / F. Analytic Philosophy / 7. Limitations of Analysis
This book says we should either say it clearly, or shut up [Wittgenstein]
1. Philosophy / G. Scientific Philosophy / 3. Scientism
Science is all the true propositions [Wittgenstein]
2. Reason / A. Nature of Reason / 1. On Reason
There is pure deductive reasoning, and explanatory demonstration reasoning [Aristotle, by Politis]
2. Reason / A. Nature of Reason / 6. Coherence
Maybe everything could be demonstrated, if demonstration can be reciprocal or circular [Aristotle]
2. Reason / B. Laws of Thought / 4. Contraries
Two falsehoods can be contrary to one another [Aristotle]
2. Reason / B. Laws of Thought / 6. Ockham's Razor
If a sign is useless it is meaningless; that is the point of Ockham's maxim [Wittgenstein]
2. Reason / D. Definition / 4. Real Definition
Definitions are of what something is, and that is universal [Aristotle]
An Aristotelian definition is causal [Aristotle, by Witt]
Definition by division needs predicates, which are well ordered and thorough [Aristotle]
You can define objects by progressively identifying what is the same and what is different [Aristotle]
2. Reason / D. Definition / 6. Definition by Essence
What it is and why it is are the same; screening defines and explains an eclipse [Aristotle]
3. Truth / B. Truthmakers / 2. Truthmaker Relation
The best account of truth-making is isomorphism [Wittgenstein, by Mulligan/Simons/Smith]
3. Truth / B. Truthmakers / 5. What Makes Truths / c. States of affairs make truths
He says the world is the facts because it is the facts which fix all the truths [Wittgenstein, by Morris,M]
3. Truth / B. Truthmakers / 11. Truthmaking and Correspondence
All truths have truth-makers, but only atomic truths correspond to them [Wittgenstein, by Rami]
3. Truth / C. Correspondence Truth / 1. Correspondence Truth
Wittgenstein's picture theory is the best version of the correspondence theory of truth [Read on Wittgenstein]
Language is [propositions-elementary propositions-names]; reality is [facts-states of affairs-objects] [Wittgenstein, by Grayling]
The account of truth in the 'Tractatus' seems a perfect example of the correspondence theory [Wittgenstein, by O'Grady]
Pictures reach out to or feel reality, touching at the edges, correlating in its parts [Wittgenstein]
3. Truth / C. Correspondence Truth / 2. Correspondence to Facts
Proposition elements correlate with objects, but the whole picture does not correspond to a fact [Wittgenstein, by Morris,M]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / e. Axioms of PL
An axiom is a principle which must be understood if one is to learn anything [Aristotle]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
Mathematical set theory has many plausible stopping points, such as finitism, and predicativism [Koellner]
'Reflection principles' say the whole truth about sets can't be captured [Koellner]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic fills the world, to its limits [Wittgenstein]
Logic concerns everything that is subject to law; the rest is accident [Wittgenstein]
5. Theory of Logic / A. Overview of Logic / 3. Value of Logic
Wittgenstein is right that logic is just tautologies [Wittgenstein, by Russell]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
Logic is a priori because it is impossible to think illogically [Wittgenstein]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
Demonstrations by reductio assume excluded middle [Aristotle]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Something holds universally when it is proved of an arbitrary and primitive case [Aristotle]
5. Theory of Logic / B. Logical Consequence / 3. Deductive Consequence |-
If q implies p, that is justified by q and p, not by some 'laws' of inference [Wittgenstein]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
The propositions of logic are analytic tautologies [Wittgenstein]
5. Theory of Logic / C. Ontology of Logic / 2. Platonism in Logic
Wittgenstein convinced Russell that logic is tautologies, not Platonic forms [Wittgenstein, by Monk]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Everything is either asserted or denied truly [Aristotle]
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
Two colours in the same place is ruled out by the logical structure of colour [Wittgenstein]
5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic
The sign of identity is not allowed in 'Tractatus' [Wittgenstein, by Bostock]
The identity sign is not essential in logical notation, if every sign has a different meaning [Wittgenstein, by Ramsey]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
Apparent logical form may not be real logical form [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
My fundamental idea is that the 'logical constants' do not represent [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not
'Not' isn't an object, because not-not-p would then differ from p [Wittgenstein]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
'Object' is a pseudo-concept, properly indicated in logic by the variable x [Wittgenstein]
5. Theory of Logic / F. Referring in Logic / 1. Naming / a. Names
Names are primitive, and cannot be analysed [Wittgenstein]
5. Theory of Logic / F. Referring in Logic / 1. Naming / c. Names as referential
A name is primitive, and its meaning is the object [Wittgenstein]
5. Theory of Logic / G. Quantification / 1. Quantification
Wittgenstein tried unsuccessfully to reduce quantifiers to conjunctions and disjunctions [Wittgenstein, by Jacquette]
5. Theory of Logic / H. Proof Systems / 1. Proof Systems
Logical proof just explicates complicated tautologies [Wittgenstein]
5. Theory of Logic / I. Semantics of Logic / 3. Logical Truth
Logical truths are just 'by-products' of the introduction rules for logical constants [Wittgenstein, by Hacking]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Aristotle's axioms (unlike Euclid's) are assumptions awaiting proof [Aristotle, by Leibniz]
Logic doesn't split into primitive and derived propositions; they all have the same status [Wittgenstein]
5. Theory of Logic / K. Features of Logics / 5. Incompleteness
We have no argument to show a statement is absolutely undecidable [Koellner]
6. Mathematics / A. Nature of Mathematics / 1. Mathematics
Mathematics is concerned with forms, not with superficial properties [Aristotle]
6. Mathematics / A. Nature of Mathematics / 2. Geometry
The essence of a triangle comes from the line, mentioned in any account of triangles [Aristotle]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / a. Units
A unit is what is quantitatively indivisible [Aristotle]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
There are at least eleven types of large cardinal, of increasing logical strength [Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
PA is consistent as far as we can accept, and we expand axioms to overcome limitations [Koellner]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / g. Incompleteness of Arithmetic
Arithmetical undecidability is always settled at the next stage up [Koellner]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / a. Defining numbers
A number is a repeated operation [Wittgenstein]
The concept of number is just what all numbers have in common [Wittgenstein]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
The theory of classes is superfluous in mathematics [Wittgenstein]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Wittgenstein hated logicism, and described it as a cancerous growth [Wittgenstein, by Monk]
The logic of the world is shown by tautologies in logic, and by equations in mathematics [Wittgenstein]
7. Existence / A. Nature of Existence / 1. Nature of Existence
The world is facts, not things. Facts determine the world, and the world divides into facts [Wittgenstein]
7. Existence / C. Structure of Existence / 6. Fundamentals / d. Logical atoms
The 'Tractatus' is an extreme example of 'Logical Atomism' [Wittgenstein, by Grayling]
In atomic facts the objects hang together like chain links [Wittgenstein]
The structure of an atomic fact is how its objects combine; this possibility is its form [Wittgenstein]
If a proposition is elementary, no other elementary proposition contradicts it [Wittgenstein]
Analysis must end in elementary propositions, which are combinations of names [Wittgenstein]
Nothing can be inferred from an elementary proposition [Wittgenstein]
7. Existence / D. Theories of Reality / 8. Facts / a. Facts
Do his existent facts constitute the world, or determine the world? [Morris,M on Wittgenstein]
7. Existence / D. Theories of Reality / 8. Facts / d. Negative facts
The world is determined by the facts, and there are no further facts [Wittgenstein]
The existence of atomic facts is a positive fact, their non-existence a negative fact [Wittgenstein]
On white paper a black spot is a positive fact and a white spot a negative fact [Wittgenstein]
8. Modes of Existence / A. Relations / 2. Internal Relations
The order of numbers is an internal relation, not an external one [Wittgenstein]
A relation is internal if it is unthinkable that its object should not possess it [Wittgenstein]
8. Modes of Existence / B. Properties / 4. Intrinsic Properties
To seek truth, study the real connections between subjects and attributes [Aristotle]
8. Modes of Existence / D. Universals / 2. Need for Universals
Separate Forms aren't needed for logic, but universals (one holding of many) are essential [Aristotle]
8. Modes of Existence / D. Universals / 6. Platonic Forms / d. Forms critiques
We can forget the Forms, as they are irrelevant, and not needed in giving demonstrations [Aristotle]
9. Objects / A. Existence of Objects / 1. Physical Objects
Objects are the substance of the world [Wittgenstein]
9. Objects / A. Existence of Objects / 5. Simples
Objects are simple [Wittgenstein]
9. Objects / A. Existence of Objects / 6. Nihilism about Objects
Why are being terrestrial and a biped combined in the definition of man, but being literate and musical aren't? [Aristotle]
9. Objects / B. Unity of Objects / 2. Substance / a. Substance
Apart from the facts, there is only substance [Wittgenstein]
9. Objects / B. Unity of Objects / 2. Substance / c. Types of substance
Units are positionless substances, and points are substances with position [Aristotle]
9. Objects / D. Essence of Objects / 4. Essence as Definition
Definitions recognise essences, so are not themselves essences [Aristotle]
9. Objects / D. Essence of Objects / 7. Essence and Necessity / c. Essentials are necessary
The predicates of a thing's nature are necessary to it [Aristotle]
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
Aristotelian essences are properties mentioned at the starting point of a science [Aristotle, by Kung]
9. Objects / D. Essence of Objects / 9. Essence and Properties
To know an object we must know the form and content of its internal properties [Wittgenstein, by Potter]
9. Objects / F. Identity among Objects / 1. Concept of Identity
Identity is not a relation between objects [Wittgenstein]
9. Objects / F. Identity among Objects / 2. Defining Identity
You can't define identity by same predicates, because two objects with same predicates is assertable [Wittgenstein]
9. Objects / F. Identity among Objects / 5. Self-Identity
Two things can't be identical, and self-identity is an empty concept [Wittgenstein]
10. Modality / A. Necessity / 2. Nature of Necessity
What is necessary cannot be otherwise [Aristotle]
10. Modality / A. Necessity / 3. Types of Necessity
The only necessity is logical necessity [Wittgenstein]
A stone travels upwards by a forced necessity, and downwards by natural necessity [Aristotle]
10. Modality / D. Knowledge of Modality / 1. A Priori Necessary
The tautologies of logic show the logic of language and the world [Wittgenstein]
10. Modality / D. Knowledge of Modality / 4. Conceivable as Possible / a. Conceivable as possible
What is thinkable is possible [Wittgenstein]
10. Modality / E. Possible worlds / 1. Possible Worlds / a. Possible worlds
Each thing is in a space of possible facts [Wittgenstein]
10. Modality / E. Possible worlds / 2. Nature of Possible Worlds / a. Nature of possible worlds
Unlike the modern view of a set of worlds, Wittgenstein thinks of a structured manifold of them [Wittgenstein, by White,RM]
An imagined world must have something in common with the real world [Wittgenstein]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
To know an object you must know all its possible occurrences [Wittgenstein]
The 'form' of an object is its possible roles in facts [Wittgenstein]
10. Modality / E. Possible worlds / 3. Transworld Objects / d. Haecceitism
Two objects may only differ in being different [Wittgenstein]
11. Knowledge Aims / A. Knowledge / 1. Knowledge
For Aristotle knowledge is explanatory, involving understanding, and principles or causes [Aristotle, by Witt]
'Episteme' means grasping causes, universal judgments, explanation, and teaching [Aristotle, by Witt]
The reason why is the key to knowledge [Aristotle]
11. Knowledge Aims / A. Knowledge / 2. Understanding
We understand a thing when we know its explanation and its necessity [Aristotle]
We only understand something when we know its explanation [Aristotle]
Some understanding, of immediate items, is indemonstrable [Aristotle]
11. Knowledge Aims / A. Knowledge / 4. Belief / c. Aim of beliefs
No one has mere belief about something if they think it HAS to be true [Aristotle]
11. Knowledge Aims / B. Certain Knowledge / 1. Certainty
Knowledge proceeds from principles, so it is hard to know if we know [Aristotle]
11. Knowledge Aims / C. Knowing Reality / 4. Solipsism
Strict solipsism is pure realism, with the self as a mere point in surrounding reality [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 2. Self-Evidence
If the truth doesn't follow from self-evidence, then self-evidence cannot justify a truth [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 5. A Priori Synthetic
The Tractatus aims to reveal the necessities, without appealing to synthetic a priori truths [Wittgenstein, by Morris,M]
There is no a priori order of things [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 8. A Priori as Analytic
Logic and maths can't say anything about the world, since, as tautologies, they are consistent with all realities [Wittgenstein, by Grayling]
12. Knowledge Sources / A. A Priori Knowledge / 10. A Priori as Subjective
Logic is a priori because we cannot think illogically [Wittgenstein]
12. Knowledge Sources / A. A Priori Knowledge / 11. Denying the A Priori
No pictures are true a priori [Wittgenstein]
12. Knowledge Sources / B. Perception / 1. Perception
You cannot understand anything through perception [Aristotle]
12. Knowledge Sources / B. Perception / 2. Qualities in Perception / d. Secondary qualities
Some knowledge is lost if you lose a sense, and there is no way the knowledge can be replaced [Aristotle]
12. Knowledge Sources / D. Empiricism / 5. Empiricism Critique
Aristotle's concepts of understanding and explanation mean he is not a pure empiricist [Aristotle, by Frede,M]
Animals may have some knowledge if they retain perception, but understanding requires reasons to be given [Aristotle]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
Many memories of the same item form a single experience [Aristotle]
13. Knowledge Criteria / A. Justification Problems / 2. Justification Challenges / a. Agrippa's trilemma
Sceptics say justification is an infinite regress, or it stops at the unknowable [Aristotle]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / b. Basic beliefs
When you understand basics, you can't be persuaded to change your mind [Aristotle]
13. Knowledge Criteria / D. Scepticism / 1. Scepticism
Doubts can't exist if they are inexpressible or unanswerable [Wittgenstein]
14. Science / A. Basis of Science / 2. Demonstration
There must be definitions before demonstration is possible [Aristotle]
All demonstration is concerned with existence, axioms and properties [Aristotle]
Demonstration is more than entailment, as the explanatory order must match the causal order [Aristotle, by Koslicki]
Aristotle gets asymmetric consequence from demonstration, which reflects real causal priority [Aristotle, by Koslicki]
Aristotle doesn't actually apply his theory of demonstration to his practical science [Leroi on Aristotle]
Premises must be true, primitive and immediate, and prior to and explanatory of conclusions [Aristotle]
We can know by demonstration, which is a scientific deduction leading to understanding [Aristotle]
Demonstrative understanding rests on necessary features of the thing in itself [Aristotle]
Demonstrations must be necessary, and that depends on the middle term [Aristotle]
Demonstrations are syllogisms which give explanations [Aristotle]
Universal demonstrations are about thought; particular demonstrations lead to perceptions [Aristotle]
Demonstration is better with fewer presuppositions, and it is quicker if these are familiar [Aristotle]
Aim to get definitions of the primitive components, thus establishing the kind, and work towards the attributes [Aristotle]
The principles of demonstrations are definitions [Aristotle]
A demonstration is a deduction which proceeds from necessities [Aristotle]
14. Science / B. Scientific Theories / 3. Instrumentalism
The 'Tractatus' is instrumentalist about laws of nature [Wittgenstein, by Armstrong]
14. Science / C. Induction / 2. Aims of Induction
Induction accepts the simplest law that fits our experiences [Wittgenstein]
We learn universals from many particulars [Aristotle]
14. Science / D. Explanation / 1. Explanation / a. Explanation
What is most universal is furthest away, and the particulars are nearest [Aristotle]
Universals are valuable because they make the explanations plain [Aristotle]
Are particulars explained more by universals, or by other particulars? [Aristotle]
14. Science / D. Explanation / 1. Explanation / b. Aims of explanation
Explanation is of the status of a thing, inferences to it, initiation of change, and purpose [Aristotle]
What we seek and understand are facts, reasons, existence, and identity [Aristotle]
14. Science / D. Explanation / 2. Types of Explanation / e. Lawlike explanations
Explanation and generality are inseparable [Aristotle, by Wedin]
The modern worldview is based on the illusion that laws explain nature [Wittgenstein]
14. Science / D. Explanation / 2. Types of Explanation / g. Causal explanations
The foundation or source is stronger than the thing it causes [Aristotle]
14. Science / D. Explanation / 3. Best Explanation / a. Best explanation
Universals give better explanations, because they are self-explanatory and primitive [Aristotle]
15. Nature of Minds / C. Capacities of Minds / 5. Generalisation by mind
Perception creates primitive immediate principles by building a series of firm concepts [Aristotle]
A perception lodging in the soul creates a primitive universal, which becomes generalised [Aristotle]
16. Persons / B. Nature of the Self / 4. Presupposition of Self
The subject stands outside our understanding of the world [Wittgenstein]
16. Persons / E. Rejecting the Self / 4. Denial of the Self
The modern idea of the subjective soul is composite, and impossible [Wittgenstein]
18. Thought / A. Modes of Thought / 6. Judgement / b. Error
The form of a proposition must show why nonsense is unjudgeable [Wittgenstein]
18. Thought / D. Concepts / 5. Concepts and Language / a. Concepts and language
What can be said is what can be thought, so language shows the limits of thought [Wittgenstein, by Grayling]
18. Thought / E. Abstraction / 2. Abstracta by Selection
We learn primitives and universals by induction from perceptions [Aristotle]
19. Language / A. Nature of Meaning / 2. Meaning as Mental
The 'form' of the picture is its possible combinations [Wittgenstein]
19. Language / A. Nature of Meaning / 4. Meaning as Truth-Conditions
To understand a proposition means to know what is the case if it is true [Wittgenstein]
19. Language / A. Nature of Meaning / 5. Meaning as Verification
Good philosophy asserts science, and demonstrates the meaninglessness of metaphysics [Wittgenstein]
19. Language / C. Assigning Meanings / 4. Compositionality
Propositions use old expressions for a new sense [Wittgenstein]
Propositions are understood via their constituents [Wittgenstein]
19. Language / D. Propositions / 2. Abstract Propositions / b. Propositions as possible worlds
Pictures are possible situations in logical space [Wittgenstein]
19. Language / F. Communication / 3. Denial
Negation takes something away from something [Aristotle]
19. Language / F. Communication / 4. Private Language
Solipsism is correct, but can only be shown, not said, by the limits of my personal language [Wittgenstein]
19. Language / F. Communication / 6. Interpreting Language / a. Translation
We translate by means of proposition constituents, not by whole propositions [Wittgenstein]
19. Language / F. Communication / 6. Interpreting Language / d. Metaphor
If you shouldn't argue in metaphors, then you shouldn't try to define them either [Aristotle]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / b. Defining ethics
Ethics cannot be put into words [Wittgenstein]
22. Metaethics / B. Value / 1. Nature of Value / c. Objective value
The sense of the world must lie outside the world [Wittgenstein]
26. Natural Theory / B. Natural Kinds / 6. Necessity of Kinds
Whatever holds of a kind intrinsically holds of it necessarily [Aristotle]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
Properties must be proved, but not essence; but existents are not a kind, so existence isn't part of essence [Aristotle]