It is more philosophical than the earlier books, because it is not so much the telling of a story or the announcement of a set of laws but the mature reflections of a leader who has spent his life moulding his people in the ways of God.
There is repetition: for example the reiteration of the Ten Commandments with editorial changes.
There is analysis: where once Israel, as the sages put it, is compelled to accept the word of God, now obedience and non-obedience are presented in terms of free will.
The material in D’varim, like the famous synagogue in Prague, is alt-neu, old and new at the same time.
The whole of subsequent Jewish history is our struggle with the covenant – with times of compliance and times of falling away. Throughout, the lesson is the same: the word of God remains firm, and the people always eventually come back to it.
There were constant dissident movements that argued with the tradition, some causing immense havoc. Some, like Sadduceeism, eventually disappeared.
Others, like Christianity, thought they could adopt and adapt what they chose, bring in elements from elsewhere and claim to have superseded the Torah way (how interesting that their Jesus lived within the Jewish framework which his followers rejected), but despite their political strength could never overcome the eternal way of Judaism.
The old was often pitted against the new, but though the old sometimes came under attack it continued to live and flourish.
Moses, for all his humility, would have every right to be proud of his work.