Combining Texts

All the ideas for 'Locke on Essences and Kinds', 'Letter to the Editor about Bayle' and 'Logical Necessity'

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


17 ideas

4. Formal Logic / D. Modal Logic ML / 3. Modal Logic Systems / h. System S5
The logic of metaphysical necessity is S5 [Rumfitt]
5. Theory of Logic / B. Logical Consequence / 1. Logical Consequence
Soundness in argument varies with context, and may be achieved very informally indeed [Rumfitt]
There is a modal element in consequence, in assessing reasoning from suppositions [Rumfitt]
We reject deductions by bad consequence, so logical consequence can't be deduction [Rumfitt]
5. Theory of Logic / D. Assumptions for Logic / 3. Contradiction
Contradictions include 'This is red and not coloured', as well as the formal 'B and not-B' [Rumfitt]
5. Theory of Logic / H. Proof Systems / 2. Axiomatic Proof
Geometrical axioms in logic are nowadays replaced by inference rules (which imply the logical truths) [Rumfitt]
9. Objects / D. Essence of Objects / 13. Nominal Essence
If kinds depend only on what can be observed, many underlying essences might produce the same kind [Eagle]
Nominal essence are the observable properties of things [Eagle]
Nominal essence mistakenly gives equal weight to all underlying properties that produce appearances [Eagle]
10. Modality / A. Necessity / 3. Types of Necessity
A distinctive type of necessity is found in logical consequence [Rumfitt, by Hale/Hoffmann,A]
10. Modality / A. Necessity / 6. Logical Necessity
Logical necessity is when 'necessarily A' implies 'not-A is contradictory' [Rumfitt]
A logically necessary statement need not be a priori, as it could be unknowable [Rumfitt]
Narrow non-modal logical necessity may be metaphysical, but real logical necessity is not [Rumfitt]
10. Modality / E. Possible worlds / 1. Possible Worlds / e. Against possible worlds
If a world is a fully determinate way things could have been, can anyone consider such a thing? [Rumfitt]
26. Natural Theory / B. Natural Kinds / 4. Source of Kinds
Kinds are fixed by the essential properties of things - the properties that make it that kind of thing [Eagle]
26. Natural Theory / D. Laws of Nature / 8. Scientific Essentialism / c. Essence and laws
In addition to laws, God must also create appropriate natures for things [Leibniz]
27. Natural Reality / A. Classical Physics / 1. Mechanics / a. Explaining movement
All that is real in motion is the force or power which produces change [Leibniz]