Combining Texts

All the ideas for 'Meno', 'Precepts for Advancing Science and Arts' and 'First-Order Logic'

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21 ideas

1. Philosophy / A. Wisdom / 1. Nature of Wisdom
Spiritual qualities only become advantageous with the growth of wisdom [Plato]
5. Theory of Logic / A. Overview of Logic / 1. Overview of Logic
Logic is the study of sound argument, or of certain artificial languages (or applying the latter to the former) [Hodges,W]
5. Theory of Logic / I. Semantics of Logic / 1. Semantics of Logic
A formula needs an 'interpretation' of its constants, and a 'valuation' of its variables [Hodges,W]
There are three different standard presentations of semantics [Hodges,W]
I |= φ means that the formula φ is true in the interpretation I [Hodges,W]
5. Theory of Logic / J. Model Theory in Logic / 3. Löwenheim-Skolem Theorems
Down Löwenheim-Skolem: if a countable language has a consistent theory, that has a countable model [Hodges,W]
Up Löwenheim-Skolem: if infinite models, then arbitrarily large models [Hodges,W]
5. Theory of Logic / K. Features of Logics / 6. Compactness
If a first-order theory entails a sentence, there is a finite subset of the theory which entails it [Hodges,W]
5. Theory of Logic / L. Paradox / 2. Aporiai
How can you seek knowledge of something if you don't know it? [Plato]
6. Mathematics / B. Foundations for Mathematics / 6. Mathematics as Set Theory / a. Mathematics is set theory
A 'set' is a mathematically well-behaved class [Hodges,W]
11. Knowledge Aims / A. Knowledge / 3. Value of Knowledge
True opinions only become really valuable when they are tied down by reasons [Plato]
12. Knowledge Sources / A. A Priori Knowledge / 3. Innate Knowledge / b. Recollection doctrine
Seeking and learning are just recollection [Plato]
The slave boy learns geometry from questioning, not teaching, so it is recollection [Plato]
13. Knowledge Criteria / A. Justification Problems / 1. Justification / b. Need for justification
As a guide to action, true opinion is as good as knowledge [Plato]
13. Knowledge Criteria / D. Scepticism / 6. Scepticism Critique
You don't need to learn what you know, and how do you seek for what you don't know? [Plato]
I don't recommend universal doubt; we constantly seek reasons for things which are indubitable [Leibniz]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / d. Teaching virtue
Is virtue taught, or achieved by practice, or a natural aptitude, or what? [Plato]
If virtue is a type of knowledge then it ought to be taught [Plato]
It seems that virtue is neither natural nor taught, but is a divine gift [Plato]
23. Ethics / C. Virtue Theory / 2. Elements of Virtue Theory / j. Unity of virtue
How can you know part of virtue without knowing the whole? [Plato]
Even if virtues are many and various, they must have something in common to make them virtues [Plato]