"As for doing good; that is one of the professions which is full. Moreover I have tried it fairly and, strange as it may seem, am satisfied that it does not agree with my constitution"

Henry David Thoreau is recommending that doing great is a worthy profession, however it is not one that he is matched for. He has actually tried it and discovered that it does not concur with his constitution. This could indicate that he has discovered it tough to do good deeds, or that he has actually found it hard to accept the benefits that feature doing excellent. It might likewise indicate that he has discovered it difficult to preserve the moral standards that come with doing excellent. Whatever the case, Thoreau is recommending that he is not matched for the profession of doing excellent, which he has discovered it challenging to maintain the standards that feature it.