His statement `` I want to make of impressionism something solid and lasting like the art in the museums '' , and his contention that he was re-creating Poussin `` after nature '' proved his desire to unite observation of nature with the permanence of classical composition . His statement `` I want to make of impressionism something solid and lasting like the art in the museums '' , and his contention that he was recreating Poussin `` after nature '' underscored his desire to unite observation of nature with the permanence of classical composition .