Combining Philosophers

All the ideas for Lucretius, Volker Halbach and Jeremiah

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102 ideas

1. Philosophy / F. Analytic Philosophy / 5. Linguistic Analysis
Analysis rests on natural language, but its ideal is a framework which revises language [Halbach]
2. Reason / D. Definition / 2. Aims of Definition
An explicit definition enables the elimination of what is defined [Halbach]
2. Reason / E. Argument / 3. Analogy
Don't trust analogies; they are no more than a guideline [Halbach]
3. Truth / A. Truth Problems / 1. Truth
The concept of truth was originated by the senses [Lucretius]
Truth-value 'gluts' allow two truth values together; 'gaps' give a partial conception of truth [Halbach]
Truth axioms prove objects exist, so truth doesn't seem to be a logical notion [Halbach]
3. Truth / A. Truth Problems / 2. Defining Truth
Any definition of truth requires a metalanguage [Halbach]
Truth definitions don't produce a good theory, because they go beyond your current language [Halbach]
Traditional definitions of truth often make it more obscure, rather than less [Halbach]
If people have big doubts about truth, a definition might give it more credibility [Halbach]
3. Truth / F. Semantic Truth / 1. Tarski's Truth / c. Meta-language for truth
In semantic theories of truth, the predicate is in an object-language, and the definition in a metalanguage [Halbach]
Semantic theories avoid Tarski's Theorem by sticking to a sublanguage [Halbach]
3. Truth / F. Semantic Truth / 2. Semantic Truth
Disquotational truth theories are short of deductive power [Halbach]
3. Truth / G. Axiomatic Truth / 1. Axiomatic Truth
Axiomatic theories of truth need a weak logical framework, and not a strong metatheory [Halbach]
CT proves PA consistent, which PA can't do on its own, so CT is not conservative over PA [Halbach]
If truth is defined it can be eliminated, whereas axiomatic truth has various commitments [Halbach]
Axiomatic truth doesn't presuppose a truth-definition, though it could admit it at a later stage [Halbach]
The main semantic theories of truth are Kripke's theory, and revisions semantics [Halbach]
To axiomatise Tarski's truth definition, we need a binary predicate for his 'satisfaction' [Halbach]
Compositional Truth CT has the truth of a sentence depending of the semantic values of its constituents [Halbach]
Gödel numbering means a theory of truth can use Peano Arithmetic as its base theory [Halbach]
Truth axioms need a base theory, because that is where truth issues arise [Halbach]
We know a complete axiomatisation of truth is not feasible [Halbach]
A theory is 'conservative' if it adds no new theorems to its base theory [Halbach, by PG]
The Tarski Biconditional theory TB is Peano Arithmetic, plus truth, plus all Tarski bi-conditionals [Halbach]
Theories of truth are 'typed' (truth can't apply to sentences containing 'true'), or 'type-free' [Halbach]
Should axiomatic truth be 'conservative' - not proving anything apart from implications of the axioms? [Halbach]
Instead of a truth definition, add a primitive truth predicate, and axioms for how it works [Halbach]
3. Truth / G. Axiomatic Truth / 2. FS Truth Axioms
Friedman-Sheard is type-free Compositional Truth, with two inference rules for truth [Halbach]
3. Truth / G. Axiomatic Truth / 3. KF Truth Axioms
The KF is much stronger deductively than FS, which relies on classical truth [Halbach]
The KF theory is useful, but it is not a theory containing its own truth predicate [Halbach]
Kripke-Feferman theory KF axiomatises Kripke fixed-points, with Strong Kleene logic with gluts [Halbach]
3. Truth / H. Deflationary Truth / 2. Deflationary Truth
Some say deflationism is axioms which are conservative over the base theory [Halbach]
Deflationists say truth merely serves to express infinite conjunctions [Halbach]
Deflationism says truth is a disquotation device to express generalisations, adding no new knowledge [Halbach]
The main problem for deflationists is they can express generalisations, but not prove them [Halbach]
Deflationists say truth is just for expressing infinite conjunctions or generalisations [Halbach]
Compositional Truth CT proves generalisations, so is preferred in discussions of deflationism [Halbach]
4. Formal Logic / E. Nonclassical Logics / 3. Many-Valued Logic
In Strong Kleene logic a disjunction just needs one disjunct to be true [Halbach]
In Weak Kleene logic there are 'gaps', neither true nor false if one component lacks a truth value [Halbach]
4. Formal Logic / F. Set Theory ST / 1. Set Theory
To prove the consistency of set theory, we must go beyond set theory [Halbach]
Every attempt at formal rigour uses some set theory [Halbach]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
The underestimated costs of giving up classical logic are found in mathematical reasoning [Halbach]
5. Theory of Logic / C. Ontology of Logic / 1. Ontology of Logic
We can use truth instead of ontologically loaded second-order comprehension assumptions about properties [Halbach]
5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic
Instead of saying x has a property, we can say a formula is true of x - as long as we have 'true' [Halbach]
5. Theory of Logic / E. Structures of Logic / 8. Theories in Logic
A theory is some formulae and all of their consequences [Halbach]
5. Theory of Logic / K. Features of Logics / 3. Soundness
You cannot just say all of Peano arithmetic is true, as 'true' isn't part of the system [Halbach]
Normally we only endorse a theory if we believe it to be sound [Halbach]
Soundness must involve truth; the soundness of PA certainly needs it [Halbach]
5. Theory of Logic / L. Paradox / 1. Paradox
Many new paradoxes may await us when we study interactions between frameworks [Halbach]
5. Theory of Logic / L. Paradox / 6. Paradoxes in Language / a. The Liar paradox
The liar paradox applies truth to a negated truth (but the conditional will serve equally) [Halbach]
6. Mathematics / B. Foundations for Mathematics / 4. Axioms for Number / d. Peano arithmetic
The compactness theorem can prove nonstandard models of PA [Halbach]
The global reflection principle seems to express the soundness of Peano Arithmetic [Halbach]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
To reduce PA to ZF, we represent the non-negative integers with von Neumann ordinals [Halbach]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / b. Type theory
Set theory was liberated early from types, and recent truth-theories are exploring type-free [Halbach]
7. Existence / C. Structure of Existence / 2. Reduction
That Peano arithmetic is interpretable in ZF set theory is taken by philosophers as a reduction [Halbach]
10. Modality / A. Necessity / 2. Nature of Necessity
Maybe necessity is a predicate, not the usual operator, to make it more like truth [Halbach]
12. Knowledge Sources / D. Empiricism / 4. Pro-Empiricism
If the senses are deceptive, reason, which rests on them, is even worse [Lucretius]
The senses are much the best way to distinguish true from false [Lucretius]
13. Knowledge Criteria / B. Internal Justification / 4. Foundationalism / c. Empirical foundations
The only possible standard for settling doubts is the foundation of the senses [Lucretius]
13. Knowledge Criteria / D. Scepticism / 3. Illusion Scepticism
Most supposed delusions of the senses are really misinterpretations by the mind [Lucretius]
14. Science / C. Induction / 1. Induction
Even simple facts are hard to believe at first hearing [Lucretius]
15. Nature of Minds / A. Nature of Mind / 1. Mind / d. Location of mind
The mind is in the middle of the breast, because there we experience fear and joy [Lucretius]
The mind is a part of a man, just like a hand or an eye [Lucretius]
15. Nature of Minds / A. Nature of Mind / 5. Unity of Mind
The separate elements and capacities of a mind cannot be distinguished [Lucretius]
16. Persons / F. Free Will / 2. Sources of Free Will
The actions of the mind are not determinate and passive, because atoms can swerve [Lucretius]
17. Mind and Body / A. Mind-Body Dualism / 2. Interactionism
Only bodies can touch one another [Lucretius]
17. Mind and Body / A. Mind-Body Dualism / 3. Panpsychism
The earth is and always has been an insentient being [Lucretius]
Particles may have sensation, but eggs turning into chicks suggests otherwise [Lucretius]
17. Mind and Body / E. Mind as Physical / 1. Physical Mind
The mind moves limbs, wakes the body up, changes facial expressions, which involve touch [Lucretius]
Lions, foxes and deer have distinct characters because their minds share in their bodies [Lucretius]
17. Mind and Body / E. Mind as Physical / 2. Reduction of Mind
You needn't be made of laughing particles to laugh, so why not sensation from senseless seeds? [Lucretius]
19. Language / D. Propositions / 4. Mental Propositions
We need propositions to ascribe the same beliefs to people with different languages [Halbach]
21. Aesthetics / C. Artistic Issues / 5. Objectivism in Art
One man's meat is another man's poison [Lucretius]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / e. Human nature
Our bodies weren't created to be used; on the contrary, their creation makes a use possible [Lucretius]
22. Metaethics / B. Value / 2. Values / e. Death
The dead are no different from those who were never born [Lucretius]
22. Metaethics / C. The Good / 3. Pleasure / e. Role of pleasure
Nature only wants two things: freedom from pain, and pleasure [Lucretius]
24. Political Theory / B. Nature of a State / 1. Purpose of a State
Jeremiah implied a link between weakness and goodness, and the evil of the state [Jeremiah, by Johnson,P]
26. Natural Theory / A. Speculations on Nature / 1. Nature
Nature runs the universe by herself without the aid of gods [Lucretius]
26. Natural Theory / A. Speculations on Nature / 5. Infinite in Nature
There can be no centre in infinity [Lucretius]
The universe must be limitless, since there could be nothing outside to limit it [Lucretius]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
Everything is created and fed by nature from atoms, and they return to atoms in death [Lucretius]
If an object is infinitely subdivisible, it will be the same as the whole universe [Lucretius]
In downward motion, atoms occasionally swerve slightly for no reason [Lucretius]
26. Natural Theory / D. Laws of Nature / 7. Strictness of Laws
Nothing can break the binding laws of eternity [Lucretius]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
If there were no space there could be no movement, or even creation [Lucretius]
Atoms move themselves [Lucretius]
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / d. Entropy
It is quicker to break things up than to assemble them [Lucretius]
27. Natural Reality / D. Time / 2. Passage of Time / a. Experience of time
We can only sense time by means of movement, or its absence [Lucretius]
27. Natural Reality / E. Cosmology / 1. Cosmology
This earth is very unlikely to be the only one created [Lucretius]
27. Natural Reality / E. Cosmology / 2. Eternal Universe
Nothing can be created by divine power out of nothing [Lucretius]
28. God / A. Divine Nature / 3. Divine Perfections
Do I not fill heaven and earth? saith the Lord [Jeremiah]
28. God / B. Proving God / 3. Proofs of Evidence / a. Cosmological Proof
If matter wasn't everlasting, everything would have disappeared by now [Lucretius]
28. God / B. Proving God / 3. Proofs of Evidence / c. Teleological Proof critique
The universe can't have been created by gods, because it is too imperfect [Lucretius]
28. God / C. Attitudes to God / 3. Deism
Am I a God afar off, and not a God close at hand? [Jeremiah]
Gods are tranquil and aloof, and have no need of or interest in us [Lucretius]
28. God / C. Attitudes to God / 5. Atheism
Why does Jupiter never hurl lightning from a blue sky? [Lucretius]
29. Religion / D. Religious Issues / 2. Immortality / a. Immortality
Spirit is mortal [Lucretius]
For a separated spirit to remain sentient it would need sense organs attached to it [Lucretius]
An immortal mind couldn't work harmoniously with a mortal body [Lucretius]
29. Religion / D. Religious Issues / 2. Immortality / b. Soul
The mind is very small smooth particles, which evaporate at death [Lucretius]
If spirit is immortal and enters us at birth, why don't we remember a previous existence? [Lucretius]