Combining Texts

All the ideas for 'What is Logic?st1=Ian Hacking', 'Letter to Mersenne' and 'Real Essentialism'

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34 ideas

2. Reason / D. Definition / 3. Types of Definition
13838 A decent modern definition should always imply a semantics [Hacking]
2. Reason / D. Definition / 5. Genus and Differentia
12249 'Animal' is a genus and 'rational' is a specific difference [Oderberg]
12242 Definition distinguishes one kind from another, and individuation picks out members of the kind [Oderberg]
4. Formal Logic / B. Propositional Logic PL / 2. Tools of Propositional Logic / d. Basic theorems of PL
13834 Gentzen's Cut Rule (or transitivity of deduction) is 'If A |- B and B |- C, then A |- C' [Hacking]
13835 Only Cut reduces complexity, so logic is constructive without it, and it can be dispensed with [Hacking]
13833 'Thinning' ('dilution') is the key difference between deduction (which allows it) and induction [Hacking]
5. Theory of Logic / A. Overview of Logic / 4. Pure Logic
13845 The various logics are abstractions made from terms like 'if...then' in English [Hacking]
5. Theory of Logic / A. Overview of Logic / 5. First-Order Logic
13840 First-order logic is the strongest complete compact theory with Löwenheim-Skolem [Hacking]
13844 A limitation of first-order logic is that it cannot handle branching quantifiers [Hacking]
5. Theory of Logic / A. Overview of Logic / 7. Second-Order Logic
13842 Second-order completeness seems to need intensional entities and possible worlds [Hacking]
5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / a. Logical connectives
13837 With a pure notion of truth and consequence, the meanings of connectives are fixed syntactically [Hacking]
5. Theory of Logic / E. Structures of Logic / 4. Variables in Logic
13839 Perhaps variables could be dispensed with, by arrows joining places in the scope of quantifiers [Hacking]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
13843 If it is a logic, the Löwenheim-Skolem theorem holds for it [Hacking]
6. Mathematics / A. Nature of Mathematics / 3. Nature of Numbers / a. Numbers
12238 The Aristotelian view is that numbers depend on (and are abstracted from) other things [Oderberg]
7. Existence / A. Nature of Existence / 3. Being / a. Nature of Being
12254 Being is substantial/accidental, complete/incomplete, necessary/contingent, possible, relative, intrinsic.. [Oderberg]
8. Modes of Existence / B. Properties / 13. Tropes / b. Critique of tropes
12253 If tropes are in space and time, in what sense are they abstract? [Oderberg]
8. Modes of Existence / C. Powers and Dispositions / 4. Powers as Essence
12256 We need to distinguish the essential from the non-essential powers [Oderberg]
9. Objects / B. Unity of Objects / 2. Substance / e. Substance critique
12252 Empiricists gave up 'substance', as unknowable substratum, or reducible to a bundle [Oderberg]
9. Objects / D. Essence of Objects / 1. Essences of Objects
12241 Essences are real, about being, knowable, definable and classifiable [Oderberg, by PG]
9. Objects / D. Essence of Objects / 3. Individual Essences
12244 Nominalism is consistent with individual but not with universal essences [Oderberg]
9. Objects / D. Essence of Objects / 6. Essence as Unifier
12240 Essentialism is the main account of the unity of objects [Oderberg]
9. Objects / D. Essence of Objects / 8. Essence as Explanatory
12247 Essence is not explanatory but constitutive [Oderberg]
9. Objects / D. Essence of Objects / 9. Essence and Properties
12258 Properties are not part of an essence, but they flow from it [Oderberg]
9. Objects / D. Essence of Objects / 15. Against Essentialism
12257 Could we replace essence with collections of powers? [Oderberg]
9. Objects / F. Identity among Objects / 8. Leibniz's Law
12236 Leibniz's Law is an essentialist truth [Oderberg]
10. Modality / B. Possibility / 4. Potentiality
12250 Bodies have act and potency, the latter explaining new kinds of existence [Oderberg]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
12234 Realism about possible worlds is circular, since it needs a criterion of 'possible' [Oderberg]
10. Modality / E. Possible worlds / 3. Transworld Objects / a. Transworld identity
12235 Necessity of identity seems trivial, because it leaves out the real essence [Oderberg]
10. Modality / E. Possible worlds / 3. Transworld Objects / b. Rigid designation
12237 Rigid designation has at least three essentialist presuppositions [Oderberg]
16. Persons / F. Free Will / 3. Constraints on the will
3789 The more reasons that compel me, the freer I am [Descartes]
26. Natural Theory / A. Speculations on Nature / 3. Natural Function
12245 Essence is the source of a thing's characteristic behaviour [Oderberg]
26. Natural Theory / A. Speculations on Nature / 6. Early Matter Theories / e. The One
12246 What makes Parmenidean reality a One rather than a Many? [Oderberg]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / a. Scientific essentialism
12239 The real essentialist is not merely a scientist [Oderberg]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / e. Anti scientific essentialism
12243 The reductionism found in scientific essentialism is mistaken [Oderberg]