4.461 A sentence shows what it says, a tautology and a contradiction [show] that they say nothing.

A tautology has no truth-conditions because it is unconditionally true; and a contradiction is true under no condition.

Tautology and contradiction are senseless [sinnlos].

(Like a point from which two arrows go out in opposite directions to one another.)

(I know nothing, e.g., about the weather if I know that it is raining or not raining.)

So a tautology tells us nothing and thus has no sense. Like a contradiction. But a tautology is always true. So somehow it corresponds to the world. How? What does it picture?