Umberto Boccioni quotes
The simultaneousness of states of mind in the work of art: that is the intoxicating aim of our art... In the pictorial description of the various states of mind of a leave-taking, perpendicular lines, undulating lines and as it were worn out, clinging here and there to silhouettes of empty bodies, may well express languidness and discouragement. Confused and trepidating lines, either straight or curved, mingled with the outlined hurried gestures of people calling to one another will express a sensation of chaotic excitement. On the other hand, horizontal lines, fleeting, rapid and jerky, brutally cutting in half lost profiles of faces or crumbling and rebounding fragments of landscape, will give the tumultuous feelings of the person going away.
Umberto Boccioni