Final answer:
In 'Of Mice and Men,' Candy lets Carlson kill his dog because it's old and suffering, influenced by peer pressure and the utilitarian mindset of that era.
Step-by-step explanation:
In John Steinbeck's novel Of Mice and Men, Candy allows Carlson to kill his dog because it was old and suffering. Although Candy is emotionally attached to the dog, who has been his companion for years, he is convinced by the other men, particularly Carlson, that the dog is no longer of any use and that it is in constant pain.
Candy is subjected to peer pressure and the prevailing attitudes of the time, which favor practicality over sentimentality. As a result, he reluctantly agrees to the mercy killing, illustrating the harsh realities of life during the Great Depression, where even the bond between a man and his pet is secondary to survival and efficiency.