After reading more of his son’s papers, why does James Jarvis leave through the front of the house rather than walking past the blood-stained floor again?

Though some of what Arthur wrote about James personally offends the older man, as Arthur indicts his father for failing to teach him a sense of greater social responsibility, James cannot help but admire his son’s selfless determination to die for a cause he believes in. By leaving through the front door, James symbolically indicates he will not dwell on his own sorrow and dwell in his son’s death, but rather use it as a catalyst for his own action and involvement in causes that are bigger than he is.