A pure mathematical series would be one in which each term is derived from the preceding term by a rule.
The first question at that time in poetry was simply the question of honesty, of sincerity.
The self is no mystery, the mystery is / That there is something for us to stand on
There are situations which cannot honorably be met by art.
Things explain each other, not themselves.
The meaning of a poem is in the cadences and the shape of the lines and the pulse of the thought which is given by those lines.