Of Mice and Men Lennie
by John Steinbeck

George’s foil, Lennie is a large, strong, doughy man unaware of his own strength. Although he’s never identified as such, Lennie clearly suffers from cognitive impairments that interfere with his ability to make decisions on his own and to remember instructions without constant repetition. Throughout the course of the novel, Lennie’s violent acts escalate in severity, as he unintentionally kills a mouse, then a puppy, and finally a human being. Lennie’s propensity for violence is alluded to in George’s reference to Lennie’s grabbing a girl’s skirt and being unable to let go in their former town of Weed. It is likely, therefore, that Lennie has a history of exhibiting such unintentional violence and would have continued to do so had he not been killed.