How does Steinbeck create sympathy for Lennie in Of Mice And Men?

He prays on our natural instinct to protect those who are less able to protect themselves, lenny is like a child, he looks at the world through a child's eye's. What ever the out come of his actions he never intends any harm, his character is sweet natured, the only people that wouldn't have sympathy for lenny are people like the less tolerant, bigoted characters of the book.