Combining Texts

All the ideas for 'Morality and Art', 'Investigations into Logical Deduction' and 'Identity'

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15 ideas

5. Theory of Logic / H. Proof Systems / 4. Natural Deduction
Natural deduction shows the heart of reasoning (and sequent calculus is just a tool) [Gentzen, by Hacking]
6. Mathematics / A. Nature of Mathematics / 4. Using Numbers / c. Counting procedure
It is controversial whether only 'numerical identity' allows two things to be counted as one [Noonan]
9. Objects / E. Objects over Time / 4. Four-Dimensionalism
I could have died at five, but the summation of my adult stages could not [Noonan]
9. Objects / E. Objects over Time / 5. Temporal Parts
Stage theorists accept four-dimensionalism, but call each stage a whole object [Noonan]
9. Objects / F. Identity among Objects / 2. Defining Identity
Problems about identity can't even be formulated without the concept of identity [Noonan]
Identity is usually defined as the equivalence relation satisfying Leibniz's Law [Noonan]
Identity definitions (such as self-identity, or the smallest equivalence relation) are usually circular [Noonan]
Identity can only be characterised in a second-order language [Noonan]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
Indiscernibility is basic to our understanding of identity and distinctness [Noonan]
Leibniz's Law must be kept separate from the substitutivity principle [Noonan]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / b. Defining ethics
Morality shows murder is wrong, but not what counts as a murder [Foot]
22. Metaethics / A. Ethics Foundations / 1. Nature of Ethics / c. Purpose of ethics
A moral system must deal with the dangers and benefits of life [Foot]
22. Metaethics / B. Value / 1. Nature of Value / c. Objective value
Saying something 'just is' right or wrong creates an illusion of fact and objectivity [Foot]
23. Ethics / D. Deontological Ethics / 6. Motivation for Duty
We sometimes just use the word 'should' to impose a rule of conduct on someone [Foot]
25. Social Practice / F. Life Issues / 3. Abortion
In the case of something lacking independence, calling it a human being is a matter of choice [Foot]