Final answer:
The passage metaphorically states that a man has lost most of his wits in a conflict and now possesses only the most basic level of intelligence, just enough to distinguish him from an animal.
Step-by-step explanation:
The passage quoted here is steeped in metaphor and implies that the subject, likely a character in a story or play, has lost the quickness of his wits due to a recent conflict.
Four out of five wits are said to have gone 'halting off,' leaving him with only one, which could suggest that he is now governed largely by base instinct or limited reasoning.
The speaker jestically notes that if the man has enough wit left to keep himself warm, he should be content with that as it differentiates him from his horse—an animal.
This implies the man is of a very low stature in terms of intellectual capability following the conflict, barely above that of a beast.
The underlying idea being conveyed is one of insult and derogation as the man's wit, an important faculty for a 'reasonable creature', is being equated to that of an animal's, and warmth—which could be a metaphor for the most basic intellectual capacity—is all he has left to assert his humanity.