Combining Philosophers

All the ideas for Plutarch, M. Tullius Cicero and Penelope Maddy

expand these ideas     |    start again     |     specify just one area for these philosophers


117 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Cicero sees wisdom in terms of knowledge, but earlier Stoics saw it as moral [Cicero, by Long]
1. Philosophy / A. Wisdom / 2. Wise People
Unfortunately we choose a way of life before we are old enough to think clearly [Cicero]
A wise man has integrity, firmness of will, nobility, consistency, sobriety, patience [Cicero]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Philosophy is the collection of rational arguments [Cicero]
2. Reason / C. Styles of Reason / 1. Dialectic
Dialectic is speech cast in the form of logical argument [Cicero]
2. Reason / F. Fallacies / 5. Fallacy of Composition
If the parts of the universe are subject to the law of nature, the whole universe must also be subject to it [Cicero]
3. Truth / A. Truth Problems / 1. Truth
There cannot be more than one truth [Cicero]
4. Formal Logic / F. Set Theory ST / 2. Mechanics of Set Theory / b. Terminology of ST
'Forcing' can produce new models of ZFC from old models [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / a. Axioms for sets
A Large Cardinal Axiom would assert ever-increasing stages in the hierarchy [Maddy]
New axioms are being sought, to determine the size of the continuum [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / b. Axiom of Extensionality I
Extensional sets are clearer, simpler, unique and expressive [Maddy]
The Axiom of Extensionality seems to be analytic [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / f. Axiom of Infinity V
The Axiom of Infinity states Cantor's breakthrough that launched modern mathematics [Maddy]
Infinite sets are essential for giving an account of the real numbers [Maddy]
Axiom of Infinity: completed infinite collections can be treated mathematically [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / g. Axiom of Powers VI
The Power Set Axiom is needed for, and supported by, accounts of the continuum [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / i. Axiom of Foundation VIII
The Axiom of Foundation says every set exists at a level in the set hierarchy [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / j. Axiom of Choice IX
Efforts to prove the Axiom of Choice have failed [Maddy]
Modern views say the Choice set exists, even if it can't be constructed [Maddy]
A large array of theorems depend on the Axiom of Choice [Maddy]
The Axiom of Choice paradoxically allows decomposing a sphere into two identical spheres [Maddy]
4. Formal Logic / F. Set Theory ST / 4. Axioms for Sets / p. Axiom of Reducibility
Axiom of Reducibility: propositional functions are extensionally predicative [Maddy]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / e. Iterative sets
The Iterative Conception says everything appears at a stage, derived from the preceding appearances [Maddy]
4. Formal Logic / F. Set Theory ST / 5. Conceptions of Set / f. Limitation of Size
Limitation of Size is a vague intuition that over-large sets may generate paradoxes [Maddy]
4. Formal Logic / F. Set Theory ST / 7. Natural Sets
The master science is physical objects divided into sets [Maddy]
Maddy replaces pure sets with just objects and perceived sets of objects [Maddy, by Shapiro]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
Henkin semantics is more plausible for plural logic than for second-order logic [Maddy]
5. Theory of Logic / C. Ontology of Logic / 3. If-Thenism
Critics of if-thenism say that not all starting points, even consistent ones, are worth studying [Maddy]
5. Theory of Logic / D. Assumptions for Logic / 1. Bivalence
How can the not-true fail to be false, or the not-false fail to be true? [Cicero]
5. Theory of Logic / D. Assumptions for Logic / 2. Excluded Middle
Dialectic assumes that all statements are either true or false, but self-referential paradoxes are a big problem [Cicero]
5. Theory of Logic / E. Structures of Logic / 1. Logical Form
'Propositional functions' are propositions with a variable as subject or predicate [Maddy]
5. Theory of Logic / K. Features of Logics / 1. Axiomatisation
Hilbert's geometry and Dedekind's real numbers were role models for axiomatization [Maddy]
If two mathematical themes coincide, that suggest a single deep truth [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / d. Actual infinite
Cantor and Dedekind brought completed infinities into mathematics [Maddy]
Completed infinities resulted from giving foundations to calculus [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / g. Continuum Hypothesis
Every infinite set of reals is either countable or of the same size as the full set of reals [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / i. Cardinal infinity
For any cardinal there is always a larger one (so there is no set of all sets) [Maddy]
An 'inaccessible' cardinal cannot be reached by union sets or power sets [Maddy]
Infinity has degrees, and large cardinals are the heart of set theory [Maddy]
6. Mathematics / A. Nature of Mathematics / 5. The Infinite / l. Limits
Theorems about limits could only be proved once the real numbers were understood [Maddy]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / c. Fregean numbers
The extension of concepts is not important to me [Maddy]
In the ZFC hierarchy it is impossible to form Frege's set of all three-element sets [Maddy]
6. Mathematics / B. Foundations for Mathematics / 5. Definitions of Number / e. Caesar problem
Frege solves the Caesar problem by explicitly defining each number [Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
Mathematics rests on the logic of proofs, and on the set theoretic axioms [Maddy]
Set theory (unlike the Peano postulates) can explain why multiplication is commutative [Maddy]
Standardly, numbers are said to be sets, which is neat ontology and epistemology [Maddy]
Numbers are properties of sets, just as lengths are properties of physical objects [Maddy]
A natural number is a property of sets [Maddy, by Oliver]
Unified set theory gives a final court of appeal for mathematics [Maddy]
Set theory brings mathematics into one arena, where interrelations become clearer [Maddy]
Identifying geometric points with real numbers revealed the power of set theory [Maddy]
Making set theory foundational to mathematics leads to very fruitful axioms [Maddy]
The line of rationals has gaps, but set theory provided an ordered continuum [Maddy]
Set-theory tracks the contours of mathematical depth and fruitfulness [Maddy]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / b. Mathematics is not set theory
Number theory doesn't 'reduce' to set theory, because sets have number properties [Maddy]
Sets exist where their elements are, but numbers are more like universals [Maddy]
6. Mathematics / C. Sources of Mathematics / 1. Mathematical Platonism / b. Against mathematical platonism
If mathematical objects exist, how can we know them, and which objects are they? [Maddy]
6. Mathematics / C. Sources of Mathematics / 2. Intuition of Mathematics
Intuition doesn't support much mathematics, and we should question its reliability [Maddy, by Shapiro]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / a. Mathematical empiricism
We know mind-independent mathematical truths through sets, which rest on experience [Maddy, by Jenkins]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / b. Indispensability of mathematics
Scientists posit as few entities as possible, but set theorist posit as many as possible [Maddy]
Maybe applications of continuum mathematics are all idealisations [Maddy]
6. Mathematics / C. Sources of Mathematics / 4. Mathematical Empiricism / c. Against mathematical empiricism
The connection of arithmetic to perception has been idealised away in modern infinitary mathematics [Maddy]
6. Mathematics / C. Sources of Mathematics / 5. Numbers as Adjectival
Number words are unusual as adjectives; we don't say 'is five', and numbers always come first [Maddy]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / c. Neo-logicism
We can get arithmetic directly from HP; Law V was used to get HP from the definition of number [Maddy]
7. Existence / D. Theories of Reality / 11. Ontological Commitment / e. Ontological commitment problems
The theoretical indispensability of atoms did not at first convince scientists that they were real [Maddy]
9. Objects / E. Objects over Time / 9. Ship of Theseus
Replacing timbers on Theseus' ship was the classic illustration of the problem of growth and change [Plutarch]
11. Knowledge Aims / C. Knowing Reality / 3. Idealism / a. Idealism
The sun is always bright; it doesn't become bright when it emerges [Plutarch]
12. Knowledge Sources / B. Perception / 1. Perception
If we have complete healthy senses, what more could the gods give us? [Cicero]
12. Knowledge Sources / E. Direct Knowledge / 4. Memory
How can there be a memory of what is false? [Cicero]
13. Knowledge Criteria / D. Scepticism / 3. Illusion Scepticism
Every true presentation can have a false one of the same quality [Cicero]
15. Nature of Minds / A. Nature of Mind / 2. Psuche
The soul is the heart, or blood in the heart, or part of the brain, of something living in heart or brain, or breath [Cicero]
When the soul is intelligent and harmonious, it is part of god and derives from god [Plutarch]
Some philosophers say the soul is light [Plutarch]
15. Nature of Minds / A. Nature of Mind / 5. Unity of Mind
How can one mind perceive so many dissimilar sensations? [Cicero]
The soul has a single nature, so it cannot be divided, and hence it cannot perish [Cicero]
15. Nature of Minds / C. Capacities of Minds / 6. Idealisation
Science idealises the earth's surface, the oceans, continuities, and liquids [Maddy]
16. Persons / B. Nature of the Self / 7. Self and Body / c. Self as brain controller
Rather than being the whole soul, maybe I am its chief part? [Plutarch]
16. Persons / C. Self-Awareness / 3. Limits of Introspection
Like the eye, the soul has no power to see itself, but sees other things [Cicero]
16. Persons / F. Free Will / 6. Determinism / a. Determinism
Whoever knows future causes knows everything that will be [Cicero]
17. Mind and Body / A. Mind-Body Dualism / 8. Dualism of Mind Critique
Why would mind mix with matter if it didn't need it? [Cicero]
17. Mind and Body / E. Mind as Physical / 7. Anti-Physicalism / a. Physicalism critique
Souls contain no properties of elements, and elements contain no properties of souls [Cicero]
If atoms have no qualities, they cannot possibly produce a mind [Plutarch]
18. Thought / A. Modes of Thought / 3. Emotions / f. Emotion and reason
Some say emotion is a sort of reason, and others say virtue concerns emotion [Plutarch]
19. Language / F. Communication / 1. Rhetoric
Oratory and philosophy are closely allied; orators borrow from philosophy, and ornament it [Cicero]
Eloquence educates, exhorts, comforts, distracts and unites us, and raises us from savagery [Cicero]
20. Action / B. Preliminaries of Action / 1. Intention to Act / c. Reducing intentions
Action needs an affinity for a presentation, and an impulse toward the affinity [Plutarch]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / g. Moral responsibility
If desire is not in our power then neither are choices, so we should not be praised or punished [Cicero]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / j. Ethics by convention
Being manly and brave is the result of convention, not of human nature [Plutarch]
22. Metaethics / C. The Good / 3. Pleasure / e. Role of pleasure
Animals don't value pleasure, as they cease sexual intercourse after impregnation [Plutarch]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Virtues must be very detached, to avoid being motivated by pleasure [Cicero]
23. Ethics / C. Virtue Theory / 3. Virtues / a. Virtues
The good life involves social participation, loyalty, temperance and honesty [Plutarch]
23. Ethics / C. Virtue Theory / 3. Virtues / f. Compassion
We should not share the distress of others, but simply try to relieve it [Cicero]
23. Ethics / C. Virtue Theory / 4. External Goods / c. Wealth
All men except philosophers fear poverty [Cicero]
23. Ethics / D. Deontological Ethics / 3. Universalisability
The essence of propriety is consistency [Cicero]
24. Political Theory / D. Ideologies / 5. Democracy / f. Against democracy
If one despises illiterate mechanics individually, they are not worth more collectively [Cicero]
25. Social Practice / D. Justice / 3. Punishment / c. Deterrence of crime
We have the death penalty, but still have thousands of robbers [Cicero]
25. Social Practice / F. Life Issues / 5. Sexual Morality
Animals have not been led into homosexuality, because they value pleasure very little [Plutarch]
26. Natural Theory / A. Speculations on Nature / 1. Nature
Some regard nature simply as an irrational force that imparts movement [Cicero]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
If only atoms exist, how do qualities arise when the atoms come together? [Plutarch]
28. God / A. Divine Nature / 4. Divine Contradictions
Why shouldn't the gods fear their own destruction? [Cicero]
28. God / A. Divine Nature / 6. Divine Morality / b. Euthyphro question
I wonder whether loss of reverence for the gods would mean the end of all virtue [Cicero]
28. God / A. Divine Nature / 6. Divine Morality / d. God decrees morality
God doesn't obey the laws of nature; they are subject to the law of God [Cicero]
28. God / B. Proving God / 2. Proofs of Reason / a. Ontological Proof
It seems clear to me that we have an innate idea of the divine [Cicero]
28. God / B. Proving God / 2. Proofs of Reason / b. Ontological Proof critique
Many primitive people know nothing of the gods [Cicero]
28. God / B. Proving God / 3. Proofs of Evidence / b. Teleological Proof
It is obvious from order that someone is in charge, as when we visit a gymnasium [Cicero]
If a person cannot feel the power of God when looking at the stars, they are probably incapable of feeling [Cicero]
If the barbarians of Britain saw a complex machine, they would be baffled, but would know it was designed [Cicero]
Chance is no more likely to create the world than spilling lots of letters is likely to create a famous poem [Cicero]
28. God / B. Proving God / 3. Proofs of Evidence / c. Teleological Proof critique
If everything with regular movement and order is divine, then recurrent illnesses must be divine [Cicero]
28. God / B. Proving God / 3. Proofs of Evidence / e. Miracles
People report seeing through rocks, or over the horizon, or impossibly small works [Plutarch]
28. God / C. Attitudes to God / 1. Monotheism
Either the gods are identical, or one is more beautiful than another [Cicero]
28. God / C. Attitudes to God / 4. God Reflects Humanity
The gods are happy, so virtuous, so rational, so must have human shape [Cicero]
28. God / C. Attitudes to God / 5. Atheism
Why believe in gods if you have never seen them? [Cicero]
Absurd superstitions make people atheist, not disharmony in nature [Plutarch]
29. Religion / D. Religious Issues / 1. Religious Commitment / a. Religious Belief
No one will ever find a city that lacks religious practices [Plutarch]
29. Religion / D. Religious Issues / 3. Problem of Evil / a. Problem of Evil
The lists of good men who have suffered and bad men who have prospered are endless [Cicero]
29. Religion / D. Religious Issues / 3. Problem of Evil / b. Human Evil
The gods blame men for having vices, but they could have given us enough reason to avoid them [Cicero]