Combining Philosophers

All the ideas for Herodotus, Fred Sommers and Hugh MacColl

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12 ideas

3. Truth / B. Truthmakers / 5. What Makes Truths / a. What makes truths

18901	Truthmakers are facts 'of' a domain, not something 'in' the domain [Sommers]
	Full Idea: A fact is an existential characteristic 'of' the domain; it is not something 'in' the domain. To search for truth-making facts in the world is indeed futile.
	From: Fred Sommers (Intellectual Autobiography [2005], 'Existence')
	A reaction: Attacking Austin on truth. Helpful. It is hard to see how a physical object has a mysterious power to 'make' a truth. No energy-transfer seems involved in the making. Animals think true thoughts; I suspect that concerns their mental maps of the world.

4. Formal Logic / A. Syllogistic Logic / 3. Term Logic

18904	'Predicable' terms come in charged pairs, with one the negation of the other [Sommers, by Engelbretsen]
	Full Idea: Sommers took the 'predicable' terms of any language to come in logically charged pairs. Examples might be red/nonred, massive/massless, tied/untied, in the house/not in the house. The idea that terms can be negated was essential for such pairing.
	From: report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2
	A reaction: If, as Rumfitt says, we learn affirmation and negation as a single linguistic operation, this would fit well with it, though Rumfitt doubtless (as a fan of classical logic) prefers to negation sentences.

18895	Logic which maps ordinary reasoning must be transparent, and free of variables [Sommers]
	Full Idea: What would a 'laws of thought' logic that cast light on natural language deductive thinking be like? Such a logic must be variable-free, conforming to normal syntax, and its modes of reasoning must be transparent, to make them virtually instantaneous.
	From: Fred Sommers (Intellectual Autobiography [2005], 'How We')
	A reaction: This is the main motivation for Fred Sommers's creation of modern term logic. Even if you are up to your neck in modern symbolic logic (which I'm not), you have to find this idea appealing. You can't leave it to the psychologists.

4. Formal Logic / F. Set Theory ST / 3. Types of Set / b. Empty (Null) Set

21548	The null class is the class with all the non-existents as its members [MacColl, by Lackey]
	Full Idea: In 1905 the Scottish logician Hugh MacColl published a paper in which he argued that the null class in logic should be taken as the class with all the non-existents as its members.
	From: report of Hugh MacColl (Symbolic Reasoning [1905]) by Douglas Lackey - Intros to Russell's 'Essays in Analysis' p.95
	A reaction: For the null object (zero) Frege just chose one sample concept with an empty extension. MacColl's set seems to have a lot of members, given that it is 'null'. How many, I wonder? Russell responded to this paper.

5. Theory of Logic / D. Assumptions for Logic / 4. Identity in Logic

18897	Predicate logic has to spell out that its identity relation '=' is an equivalent relation [Sommers]
	Full Idea: Because predicate logic contrues identities dyadically, its account of inferences involving identity propositions needs laws or axioms of identity, explicitly asserting that the dyadic realtion in 'x=y' possesses symmetry, reflexivity and transitivity.
	From: Fred Sommers (Intellectual Autobiography [2005], 'Syllogistic')

5. Theory of Logic / E. Structures of Logic / 1. Logical Form

18893	Translating into quantificational idiom offers no clues as to how ordinary thinkers reason [Sommers]
	Full Idea: Modern predicate logic's methods of justification, which involve translation into an artificial quantificational idiom, offer no clues to how the average person, knowing no logic and adhering to the vernacular, is so logically adept.
	From: Fred Sommers (Intellectual Autobiography [2005], Intro)
	A reaction: Of course, people are very logically adept when the argument is simple (because, I guess, they can test it against the world), but not at all good when the reasoning becomes more complex. We do, though, reason in ordinary natural language.

5. Theory of Logic / E. Structures of Logic / 2. Logical Connectives / c. not

18903	Sommers promotes the old idea that negation basically refers to terms [Sommers, by Engelbretsen]
	Full Idea: If there is one idea that is the keystone of the edifice that constitutes Sommers's united philosophy it is that terms are the linguistic entities subject to negation in the most basic sense. It is a very old idea, tending to be rejected in modern times.
	From: report of Fred Sommers (Intellectual Autobiography [2005]) by George Engelbretsen - Trees, Terms and Truth 2
	A reaction: Negation in modern logic is an operator applied to sentences, typically writing '¬Fa', which denies that F is predicated of a, with Fa being an atomic sentence. Do we say 'not(Stan is happy)', or 'not-Stan is happy', or 'Stan is not-happy'? Third one?

5. Theory of Logic / E. Structures of Logic / 7. Predicates in Logic

18894	Predicates form a hierarchy, from the most general, down to names at the bottom [Sommers]
	Full Idea: We organise our concepts of predicability on a hierarchical tree. At the top are terms like 'interesting', 'exists', 'talked about', which are predicable of anything. At the bottom are names, and in between are predicables of some things and not others.
	From: Fred Sommers (Intellectual Autobiography [2005], 'Category')
	A reaction: The heirarchy seem be arranged simply by the scope of the predicate. 'Tallest' is predicable of anything in principle, but only of a few things in practice. Is 'John Doe' a name? What is 'cosmic' predicable of? Challenging!

7. Existence / D. Theories of Reality / 2. Realism

18900	Unfortunately for realists, modern logic cannot say that some fact exists [Sommers]
	Full Idea: Unfortunately for the fate of realist philosophy, modern logic's treatment of 'exists' is resolutely inhospitable to facts as referents of phrases of the form 'the existence or non-existence of φ'.
	From: Fred Sommers (Intellectual Autobiography [2005], 'Realism')
	A reaction: Predicate logic has to talk about objects, and then attribute predicates to them. It tends to treat a fact as 'Fa' - this object has this predicate, but that's not really how we understand facts.

7. Existence / E. Categories / 1. Categories

13127	Categories can't overlap; they are either disjoint, or inclusive [Sommers, by Westerhoff]
	Full Idea: Fred Sommers, in his treatment of types, says that two ontological categories cannot overlap; they are either disjoint, or one properly includes the other. This is sometimes referred to as Sommers' Law.
	From: report of Fred Sommers (Types and Ontology [1963], p.355) by Jan Westerhoff - Ontological Categories §24
	A reaction: The 'types', of course, go back to Bertrand Russell's theory of types, which is important in discussions of ontological categories. Carnap pursued it, trying to derive ontological categories from grammatical categories. 85% agree with Sommers.

19. Language / B. Reference / 1. Reference theories

18898	In standard logic, names are the only way to refer [Sommers]
	Full Idea: In modern predicate logic, definite reference by proper names is the primary and sole form of reference.
	From: Fred Sommers (Intellectual Autobiography [2005], 'Reference')
	A reaction: Hence we have to translate definite descriptions into (logical) names, or else paraphrase them out of existence. The domain only contains 'objects', so only names can uniquely pick them out.

29. Religion / D. Religious Issues / 2. Immortality / a. Immortality

1513	The Egyptians were the first to say the soul is immortal and reincarnated [Herodotus]
	Full Idea: The Egyptians were the first to claim that the soul of a human being is immortal, and that each time the body dies the soul enters another creature just as it is being born.
	From: Herodotus (The Histories [c.435 BCE], 2.123.2)