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All the ideas for 'Thinking About Mathematics', 'Frege philosophy of mathematics' and 'Critique of Practical Reason'

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76 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Wisdom is knowing the highest good, and conforming the will to it [Kant]
1. Philosophy / D. Nature of Philosophy / 3. Philosophy Defined
What fills me with awe are the starry heavens above me and the moral law within me [Kant]
1. Philosophy / D. Nature of Philosophy / 5. Aims of Philosophy / e. Philosophy as reason
Consistency is the highest obligation of a philosopher [Kant]
1. Philosophy / E. Nature of Metaphysics / 5. Metaphysics beyond Science
Metaphysics is just a priori universal principles of physics [Kant]
2. Reason / D. Definition / 7. Contextual Definition
A contextual definition permits the elimination of the expression by a substitution [Dummett]
5. Theory of Logic / A. Overview of Logic / 6. Classical Logic
In classical logic, logical truths are valid formulas; in higher-order logics they are purely logical [Dummett]
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]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / b. Types of number
A prime number is one which is measured by a unit alone [Dummett]
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 / c. Priority of numbers
Addition of quantities is prior to ordering, as shown in cyclic domains like angles [Dummett]
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 / A. Nature of Mathematics / 4. Using Numbers / a. Units
A number is a multitude composed of units [Dummett]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / e. Counting by correlation
We understand 'there are as many nuts as apples' as easily by pairing them as by counting them [Dummett]
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 / B. Foundations for Mathematics / 7. Mathematical Structuralism / e. Structuralism critique
The identity of a number may be fixed by something outside structure - by counting [Dummett]
Numbers aren't fixed by position in a structure; it won't tell you whether to start with 0 or 1 [Dummett]
6. Mathematics / C. Sources of Mathematics / 6. Logicism / d. Logicism critique
Set theory isn't part of logic, and why reduce to something more complex? [Dummett]
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
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 / C. Structure of Existence / 7. Abstract/Concrete / a. Abstract/concrete
The distinction of concrete/abstract, or actual/non-actual, is a scale, not a dichotomy [Dummett]
7. Existence / D. Theories of Reality / 2. Realism
Realism is just the application of two-valued semantics to sentences [Dummett]
8. Modes of Existence / E. Nominalism / 1. Nominalism / a. Nominalism
Nominalism assumes unmediated mental contact with objects [Dummett]
9. Objects / A. Existence of Objects / 2. Abstract Objects / a. Nature of abstracta
The existence of abstract objects is a pseudo-problem [Dummett]
9. Objects / A. Existence of Objects / 2. Abstract Objects / c. Modern abstracta
Abstract objects nowadays are those which are objective but not actual [Dummett]
It is absurd to deny the Equator, on the grounds that it lacks causal powers [Dummett]
'We've crossed the Equator' has truth-conditions, so accept the Equator - and it's an object [Dummett]
9. Objects / A. Existence of Objects / 2. Abstract Objects / d. Problems with abstracta
Abstract objects need the context principle, since they can't be encountered directly [Dummett]
9. Objects / F. Identity among Objects / 2. Defining Identity
Content is replaceable if identical, so replaceability can't define identity [Dummett, by Dummett]
Frege introduced criteria for identity, but thought defining identity was circular [Dummett]
10. Modality / C. Sources of Modality / 1. Sources of Necessity
Necessity cannot be extracted from an empirical proposition [Kant]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
18. Thought / D. Concepts / 4. Structure of Concepts / i. Conceptual priority
Maybe a concept is 'prior' to another if it can be defined without the second concept [Dummett]
An argument for conceptual priority is greater simplicity in explanation [Dummett]
18. Thought / E. Abstraction / 1. Abstract Thought
Abstract terms are acceptable as long as we know how they function linguistically [Dummett]
18. Thought / E. Abstraction / 7. Abstracta by Equivalence
There is no reason why abstraction by equivalence classes should be called 'logical' [Dummett, by Tait]
We arrive at the concept 'suicide' by comparing 'Cato killed Cato' with 'Brutus killed Brutus' [Dummett]
18. Thought / E. Abstraction / 8. Abstractionism Critique
To abstract from spoons (to get the same number as the forks), the spoons must be indistinguishable too [Dummett]
19. Language / C. Assigning Meanings / 5. Fregean Semantics
Fregean semantics assumes a domain articulated into individual objects [Dummett]
20. Action / B. Preliminaries of Action / 2. Willed Action / a. Will to Act
Can pure reason determine the will, or are empirical conditions relevant? [Kant]
The will is the faculty of purposes, which guide desires according to principles [Kant]
20. Action / C. Motives for Action / 3. Acting on Reason / a. Practical reason
The sole objects of practical reason are the good and the evil [Kant]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / b. Rational ethics
Only human reason can confer value on our choices [Kant, by Korsgaard]
22. Metaethics / A. Ethics Foundations / 2. Source of Ethics / h. Expressivism
People cannot come to morality through feeling, because morality must not be sensuous [Kant]
22. Metaethics / B. Value / 1. Nature of Value / f. Ultimate value
Kant may rate two things as finally valuable: having a good will, and deserving happiness [Orsi on Kant]
An autonomous agent has dignity [Würde], which has absolute worth [Kant, by Pinkard]
The good will is unconditionally good, because it is the only possible source of value [Kant, by Korsgaard]
Good or evil cannot be a thing, but only a maxim of action, making the person good or evil [Kant]
22. Metaethics / C. The Good / 1. Goodness / g. Consequentialism
Morality involves duty and respect for law, not love of the outcome [Kant]
22. Metaethics / C. The Good / 2. Happiness / a. Nature of happiness
Our happiness is all that matters, not as a sensation, but as satisfaction with our whole existence [Kant]
Happiness is the condition of a rational being for whom everything goes as they wish [Kant]
22. Metaethics / C. The Good / 2. Happiness / c. Value of happiness
Morality is not about making ourselves happy, but about being worthy of happiness [Kant]
23. Ethics / C. Virtue Theory / 1. Virtue Theory / a. Nature of virtue
The highest worth for human beings lies in dispositions, not just actions [Kant]
Virtue is the supreme state of our pursuit of happiness, and so is supreme good [Kant]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / c. Motivation for virtue
Moral law is holy, and the best we can do is achieve virtue through respect for the law [Kant]
23. Ethics / D. Deontological Ethics / 3. Universalisability
No one would lend money unless a universal law made it secure, even after death [Kant]
Universality determines the will, and hence extends self-love into altruism [Kant]
23. Ethics / D. Deontological Ethics / 5. Persons as Ends
Everyone (even God) must treat rational beings as ends in themselves, and not just as means [Kant]
23. Ethics / D. Deontological Ethics / 6. Motivation for Duty
A holy will is incapable of any maxims which conflict with the moral law [Kant]
Reason cannot solve the problem of why a law should motivate the will [Kant]
25. Social Practice / F. Life Issues / 4. Suicide
A permanent natural order could not universalise a rule permitting suicide [Kant]
27. Natural Reality / C. Space / 3. Points in Space
Why should the limit of measurement be points, not intervals? [Dummett]
28. God / A. Divine Nature / 6. Divine Morality / b. Euthyphro question
Obligation does not rest on the existence of God, but on the autonomy of reason [Kant]
28. God / B. Proving God / 2. Proofs of Reason / c. Moral Argument
We have to postulate something outside nature which makes happiness coincide with morality [Kant]
Belief in justice requires belief in a place for justice (heaven), a time (eternity), and a cause (God) [Kant, by PG]
28. God / B. Proving God / 3. Proofs of Evidence / a. Cosmological Proof
To know if this world must have been created by God, we would need to know all other possible worlds [Kant]
28. God / B. Proving God / 3. Proofs of Evidence / c. Teleological Proof critique
Using God to explain nature is referring to something inconceivable to explain what is in front of you [Kant]
From our limited knowledge we can infer great virtues in God, but not ultimate ones [Kant]
28. God / C. Attitudes to God / 4. God Reflects Humanity
In all naturalistic concepts of God, if you remove the human qualities there is nothing left [Kant]