In the very, very simplest terms, judging the validity of an argument starts centers around this process:
1) Identify the rhetoric (Lines of Argument) from the actual, formal reasons. Separate the persuasive language from the actual claims to truth and fact.
2) Analyze those reasons (claims to truth and fact) by identifying their logic (often in the Implicit Reasons) and evidence.
3) Test and evaluate the logic and evidence; identify logical errors and ask whether the evidence can and has been tested and objectively, repeatedly, factually verified.
Answer:
The mood here is one of uncertainty, the character is not exactly afraid but he is most certainly in an unknown place. His first reaction is to take in his surroundings and analyze his position. This shows ,in this scene at least, that the character is not one to be scared of unusual circumstances.
5. A means through which something is done.
