Expressive architecture:
An essential part of Poussin's style is the artist's "theory of the modes," which held that each and every element of a painting (line, color, form) had a significant psychological impact on the viewer.
According to art historian Yona Pinson, in Massacre of the Innocents, even the architecture is intended to have an emotional effect. The heavy, dark, foreboding column which dominates the left-hand side of the picture plane is intended to express the obdurate forces of evil, as represented by the grimacing soldier who is about to chop off the head of the wailing baby he crushes beneath his foot.
The Greek temple in the background of the picture, on the other hand, represents the opposite. This temple is decorated with the Corinthian order which, according to ancient Greek architect Vitruvius, represented the feminine principle. In this painting, Poussin intends this Corinthian temple to represent the feminine frailty and helplessness of the bereaved mothers.