Full Idea
It has been found useful in defining semantical concepts to deal first with the concept of satisfaction; both because the definition of this concept presents relatively few difficulties, and because the other semantical concepts are easily reduced to it.
Gist of Idea
Satisfaction is the easiest semantical concept to define, and the others will reduce to it
Source
Alfred Tarski (The Establishment of Scientific Semantics [1936], p.406)
Book Reference
Tarski,Alfred: 'Logic, Semantics, Meta-mathematics' [Hackett 1956], p.406
A Reaction
See Idea 13339 for his explanation of satisfaction. We just say that a open sentence is 'acceptable' or 'assertible' (or even 'true') when particular values are assigned to the variables. Then sentence is then 'satisfied'.
Related Idea
Idea 13339 A sentence is satisfied when we can assert the sentence when the variables are assigned [Tarski]