II 29
Def Concept: a concept is a function whose value is always a truth value.
Concept: a concept is not an object in itself, while the concept scope (value progression, i.e. with an inserted value for the variable) is an object.
>
Object, >
Truth value, >
Function.
II 66 f
Concept: a concept is predicative, unsaturated and not an object.
The inclusion of an object in a concept is an irreversible relation.
E.g. "The morning star is nothing but Venus" but not "Venus is nothing but the morning star."
II 66 f
An equation is reversible, a predication is irreversible (intension, false: "Venus is nothing but the morning star.")
>
Intension, >
Identity.
II 66
The "meaning" of a name is never a concept (predicate) but always only a subject.
A concept is not an object. The "meaning" (reference): is an object.
E.g. the concept horse is not a concept (but just an object).
Similarly: E.g. "This rose is red" and we say: "The grammatical predicate" "is red" is part of the subject "this rose". Here, the words "The grammatical predicate" "is red" are not a grammatical predicate but a subject.
This is difficult to grasp, the city of Berlin being a city and the volcano Vesuvius being a volcano.
II 71
>
Subject, >
Predicate.
Because of its predicative nature the concept cannot appear readily as a subject, but must be transformed into an object first, more precisely: it must be represented by an object. E.g. "The concept human is not empty." Here, the first three words are to be regarded as a proper name.
Def Concept: Meaning of a predicate. ((s) QuineVs: >
Predicates/Quine, >
Properties/Quine, >
Meaning/Quine).
II 74
Number/Numbers/Concept/Object/Frege: Figures are statements about a concept. E.g. "There is at least one root of 4" is not about a specific number 2 but about a concept: the root of 4. On the contrary: e.g. "The concept root of 4 is fulfilled": the first 5 words form the name of an object. Something is being said about an object. Fulfillment/Frege/(s): fulfillment is not a property of a concept, but of an object. The fulfilled object is the concept. >
Satisfaction.
II 80
Object/Relation/Frege: Problem: with the words. "The relation of being included in an object": we mean no relation but an object - ((s) the words are the name of the relation, the relation is an object).
I 82
Concept/Frege: E.g. "All whales are mammals" is about concepts - not a single animal can be shown. It is better than to speak of an "indefinite object" >
number: not the objects but the concepts are the carriers of the number.
IV 110
Concept/Frege: whether a term is contradictory must be shown through research.
- - -
Tugendhat I 195f
Concept/Frege: "logical basic relationship": is the inclusion of an object in a concept", whether it is properly applied: is not a logical, but empirical question.