Combining Texts

All the ideas for 'Thinking About Mathematics', 'Internal and External Reasons' and 'Letters to Samuel Clarke'

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31 ideas

2. Reason / B. Laws of Thought / 2. Sufficient Reason
The principle of sufficient reason is needed if we are to proceed from maths to physics [Leibniz]
There is always a reason why things are thus rather than otherwise [Leibniz]
No reason could limit the quantity of matter, so there is no limit [Leibniz]
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
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
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 / 6. Fundamentals / c. Monads
All simply substances are in harmony, because they all represent the one universe [Leibniz]
8. Modes of Existence / A. Relations / 1. Nature of Relations
The ratio between two lines can't be a feature of one, and cannot be in both [Leibniz]
12. Knowledge Sources / C. Rationalism / 1. Rationalism
Rationalism tries to apply mathematical methodology to all of knowledge [Shapiro]
20. Action / C. Motives for Action / 3. Acting on Reason / c. Reasons as causes
Reasons are 'internal' if they give a person a motive to act, but 'external' otherwise [Williams,B]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / g. Atomism
The only simple things are monads, with no parts or extension [Leibniz]
Atomism is irrational because it suggests that two atoms can be indistinguishable [Leibniz]
Things are infinitely subdivisible and contain new worlds, which atoms would make impossible [Leibniz]
27. Natural Reality / A. Classical Physics / 2. Thermodynamics / c. Conservation of energy
Leibniz upheld conservations of momentum and energy [Leibniz, by Papineau]
27. Natural Reality / C. Space / 4. Substantival Space
The idea that the universe could be moved forward with no other change is just a fantasy [Leibniz]
27. Natural Reality / D. Time / 1. Nature of Time / b. Relative time
Space and time are purely relative [Leibniz]
27. Natural Reality / D. Time / 1. Nature of Time / i. Denying time
No time exists except instants, and instants are not even a part of time, so time does not exist [Leibniz]
27. Natural Reality / D. Time / 2. Passage of Time / a. Experience of time
If everything in the universe happened a year earlier, there would be no discernible difference [Leibniz]
28. God / A. Divine Nature / 5. God and Time
If time were absolute that would make God's existence dependent on it [Leibniz, by Bardon]
28. God / B. Proving God / 3. Proofs of Evidence / a. Cosmological Proof
The existence of God, and all metaphysics, follows from the Principle of Sufficient Reason [Leibniz]