How does the Dutch painter come to a space based on a relationship between horizontal and vertical straight lines?
The artist begins to paint in accordance with the tested canons of the naturalistic painting, otherwise called figurative:
Around 1907, the earlier landscapes of the naturalist phase are stripped of trees, houses, and any sign of human presence and seem to want to express an unspoiled nature:
As art historian H. L. C. Jaffé observes, “His confrontation in 1909 with the infinity of nature coincides with his joining the Netherlands Theosophical Society, where man’s union with the infinitude of the universe was a central problem.”
At the same time the painter’s attention turns to constructions such as mills or lighthouses:
In the compositions that expand horizontally, the gaze is opened to the infinite dimension of nature while in the vertical architectural volumes everything is concentrated in a finite space in which human beings think, design and build to rise from a primitive condition of nature. The vertical elevation expresses mankind’s atavistic propensity to imagine the spiritual extending toward the ethereal space of the heavens rather than remaining bound to the everyday matter spread out horizontally before our eyes.
The artist ascribed to the horizontal the value of everything that can be defined as the “natural” not only in the sense of natural landscape but also as anything that before our eyes and within ourselves in the course of our lives constantly changes, transforms, evolves. In the vertical the artist instead saw a symbol of the “spiritual” that is, of the all-human propensity to seek stability, constancy, unity. Consciousness arises from this interaction between mutable and constant, multiplicity and unity, instincts and reason, that is to say, between opposite drives. How to express opposite drives in the bi-dimensional space of painting? A way is to generate a dynamic interaction between horizontal and vertical directions.
While an horizontal extension prevails in the natural landscapes and a vertical development in the architectures, the opposite directions seem to interpenetrate in the figure of a bare tree:
In the structure of a tree Mondrian seems to want to suggest a synthesis of horizontal and vertical, that is, of the natural and the spiritual.
The later abstract compositions formed by horizontal and vertical lines are already present in the figure of the tree although still in a form veiled by appearances.