How did Wassily Kandinsky believe colors, lines, and shapes could express emotions?

Wassily Kandinsky sought to develop a visual "language" that, much like music, could express general ideas and evoke deep emotions by freeing colors, lines, and shapes from the need to depict recognizable objects.1

In his influential treatise, Concerning the Spiritual in Art, Kandinsky explored the expressive potential of colors. He famously drew parallels between visual elements and musical sounds, comparing yellow to the aggressive, earthly tone of a trumpet and blue to the heavenly sound of a pipe organ.2

Later, during his tenure at the Bauhaus, Kandinsky expanded his theoretical framework to include the psychological effects of drawing elements. He analyzed these forms through a systematic lens, interpreting a horizontal line as cold and a vertical line as hot. He also viewed geometric shapes as carriers of profound meaning; for instance, he considered the circle to be a primary form that pointed toward the fourth dimension and contained immense, beautiful opposition. Through these theories, he aimed to unite the inner world of feeling with the outer world of form and color.234