"I wish to warn young men against the invincible attraction of theories which simplify and unify seductively... We fall into the trap all the more readily when the simple schemes stimulate and appeal to tendencies deeply rooted in our minds, the congenital inclination to economy of mental effort and the almost irresistible propensity to regard as true what satisfies our aesthetic sensibility by appearing in agreeable and harmonious architectural forms. As always, reason is silent before beauty." From Recollections of My Life

This image shows details of the spinal cord. Cajal's patient investigation revealed the elaborate organization of the fibers that course between the spine and brain. The top image is a lateral view of the spinal cord; along the left, motor nerves connect to muscles, and along the right, a sensory nerve (red) snakes down to the skin.

The bottom image is a cross section showing motor cells (black) in the spinal cord.