The taking of the Vietnamese soldier’s thumb as a souvenir of war shows how war changes young men into uncivilized human beings. When Sanders is making the statement, “There it is”, he is talking about how this barbaric act shows what happens when you send young, innocent men off to war. War changes young men, and they will come back changed and psychologically affected by the things they see and do. Tim O’Brien often mentions throughout the novel that “they are, after all, only kids”, and suggests to the reader that if you send kids to war, they will come back men who have done horrible things. This is also seen in the vignette, “How to Tell a True War Story” when Rat Kiley methodically kills a baby water buffalo by wounding it over and over again until it dies. The water buffalo just stands there and takes it without making a move to escape. The water buffalo is like the soldiers who are psychologically wounded during their many experiences in the war. These wounds cause them to do unnatural, barbaric things.
The “there it is” moral that Sanders suggests exists by the taking of a souvenir of your enemy is that these atrocities are going to happen when men go to war. The thumb is a symbol of those atrocities and show just how inhumane man can be in an inhumane war. Sanders is simply pointing that out when he says, “There it is”. “There it is” means look how far we have fallen, and look at what war causes us to do.
At first, Mitchell Sanders is not articulate or expansive in expressing the meaning and moral of the severed thumb. The most he can do is to point to the dead man and say, "There it is, man" (paragraph 37). Dobbins says that there is no moral. Later on (paragraph 75), the men consider the moral further. A reader might wish to contemplate what it means to repeat "there it is" as an "act of poise" and the further meaning of "you can’t change what can’t be changed." This matter-of-fact statement suggests some sort of cosmic irony in that, it is true, there something is, but they themselves find they are in one of the most inhospitable places at a time that was severely controversial, not only to the soldiers, but to the general American population at the time.