Cajal the artist. The origins of a passion.

Santiago Ramón y Cajal is widely recognized as the father of modern neuroscience. However, his life has many extraordinary facets, and he is even considered a polymath. Among his many activities, his artistic endeavors stand out, and this article focuses on exploring the origins of Cajal's passion for the arts. The Aragonese scholar cultivated drawing, painting, literature, chess, and, notably, photography with equal intensity and passion. This article shows Cajal's artistic dimension, exploring the origins and evolution of his passion for drawing, painting, and photography. We demonstrate that his profound visual capacity and the technical skill developed through his art were not unrelated to his scientific work. On the contrary, they became the fundamental support for his ability to innovate and document the delicate structures of the nervous system through beautiful drawings and photographs that allowed him to show humanity the "butterflies of the soul," the name he gave to the elegant cells he saw in nervous tissue. His inclination for drawing was evident from childhood, and despite serious conflicts with his father, who desperately wanted him to become a doctor, he managed to take painting courses and perfect his technique. His work as a painter, writer, and photographer is presented, leaving the door open for future explorations into the life of a great man who continues to amaze almost a century after his passing.