In a letter to the American botanist Asa Gray, Darwin wrote:
But I own that I cannot see, as plainly as others do, & as I shd wish to do, evidence of design & beneficence on all sides of us. There seems to me too much misery in the world. I cannot persuade myself that a beneficent & omnipotent God would have designedly created the Ichneumonidæ with the express intention of their feeding within the living bodies of caterpillars, or that a cat should play with mice.
The other day I saw a cat catch a mouse at Mudchute Farm. But perhaps unnerved by my presence, it did not play with its prey. Instead it retreated post-haste under a nearby wagon to finish its lunch, occasionally stealing mistrustful glances in my direction.