Combining Texts

All the ideas for 'Phenomenalism', 'Completeness of Axioms of Logic' and 'Intro to I: Classical Logic'

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4 ideas

4. Formal Logic / C. Predicate Calculus PC / 3. Completeness of PC

17751	Gödel proved the completeness of first order predicate logic in 1930 [Gödel, by Walicki]
	Full Idea: Gödel proved the completeness of first order predicate logic in his doctoral dissertation of 1930.
	From: report of Kurt Gödel (Completeness of Axioms of Logic [1930]) by Michal Walicki - Introduction to Mathematical Logic History E.2.2

5. Theory of Logic / A. Overview of Logic / 6. Classical Logic

9463	Classical logic is bivalent, has excluded middle, and only quantifies over existent objects [Jacquette]
	Full Idea: Classical logic (of Whitehead, Russell, Gödel, Church) is a two-valued system of propositional and predicate logic, in which all propositions are exclusively true or false, and quantification and predication are over existent objects only.
	From: Dale Jacquette (Intro to I: Classical Logic [2002], p.9)
	A reaction: All of these get challenged at some point, though the existence requirement is the one I find dubious.

11. Knowledge Aims / C. Knowing Reality / 2. Phenomenalism

2614	Modern phenomenalism holds that objects are logical constructions out of sense-data [Ayer]
	Full Idea: Nowadays phenomenalism is held to be a theory of perception which says that physical objects are logical constructions out of sense-data.
	From: A.J. Ayer (Phenomenalism [1947], §1)

12. Knowledge Sources / B. Perception / 4. Sense Data / a. Sense-data theory

2615	The concept of sense-data allows us to discuss appearances without worrying about reality [Ayer]
	Full Idea: The introduction of the term 'sense-datum' is a means of referring to appearances without prejudging the question of what it is, if anything, that they are appearances of.
	From: A.J. Ayer (Phenomenalism [1947], §1)