Sunday Under Three Heads seems at first to be one of Dickens's delightful urban sketches. His subject, at least in the first chapter, is simply the different types of people one meets on a typical Sunday morning walk. But in the second chapter, he describes what Sunday morning would look like if the Christian ""fanatics"" in Parliament had been able to pass a recent bill changing the Sabbath trade laws. In the third chapter he discusses what he thinks life on Sunday ought ideally to be like.

You were among the first, some years ago, to expatiate on the vicious addiction of the lower classes of society to Sunday excursions; and were thus instrumental in calling forth occasional demonstrations of those extreme opinions on the subject, which are very generally received with derision, if not with contempt.