Final answer:
The provided text requires context to determine why Walter says he has called 'the man' and what he has learned. Walter's actions and reasons for calling Lindner depend on the specific plot of the literary work they are from.
Step-by-step explanation:
The question relates to a play in which the character Walter announces that he has called 'the man,' referring to a character named Lindner.
The exact context of what Walter has learned is not provided in the excerpts given.
However, generally, when Walter says he called 'the man' in literature, it might indicate a turning point or decision that the character has made which can involve a resolution or a new conflict.
The reason Walter called Lindner would be based on the specific plot of the work in question.
Without the context of which play or book these characters are from, it is impossible to provide a factual and detailed response to the student's question.
It would be imperative to know the title of the work to answer accurately why Walter called Lindner and what he learned from it.