In The Night Thoreau Spent in Jail, is Henry's refusal to pay taxes wise or foolish?
On one level, Thoreau's defense for not paying the taxes makes sense. If Thoreau believes that the war is wrong and that the taxes citizens pay end up financing that war, then Thoreau refuses to be a part of this configuration. On some levels, this makes sense based on Henry's explanations for a couple of reasons. The first is that Thoreau's fundamental rift with Emerson is that the latter does not practice what he preaches. Thoreau cannot live with such hypocrisy. For Thoreau, he has such a high moral standard that if he critiqued Emerson for not being consistent with his beliefs and value systems being preached, then by definition, it makes perfect sense for Thoreau to stand up for his beliefs and not pay the taxes when he believes that the money collected by the government is wrong. On another level, Thoreau's point in standing for his beliefs is that people must not have their voice silenced by social orders or political ones. His refusal to pay taxes is an example of this, indicating some level of wisdom present.
Yet, I think that Thoreau's character evolves throughout the drama. Thoreau is upset that his Aunt Louisa paid the taxes. However, in this moment, he also understands that the cause for which he pledges his beliefs might be larger than his own individual actions. If Thoreau is right and that the war is a moral evil against which individual voice must be articulated, then his sitting in jail over a refusal to pay the tax becomes a sideshow. Thoreau is developed in a manner that he recognizes the "higher" calling present. He understands that him sitting in a jail is not as important as him being present in a "more active stand" against the war as opposed to being isolated in a jail cell. I think that in this, Thoreau would not see his refusal to pay the taxes as foolish, but one in which larger interests and concerns are present.
This is going to be one of those questions that it is actually quite hard to answer conclusively, as the answer will depend very much on your own individual opinion and ideas, especially concerning the beliefs of Thoreau. Certainly, I think we need to say that for Henry, not paying his taxes was an important form of protest that enabled him to continue to develop his own ideas about activism and what he believed in and what he wanted to stand against. Let us remember that in Act One he explains his position, saying that he did not pay his taxes because he disagreed with the way that the money was being spent as it supported the war in Mexico that he was against.
However, equally you could argue that Henry was stupid not to pay his taxes as it meant he got put in jail. For Henry, however, conforming to society is something that is an anethema for him, and remember that he says at one stage he is actually more free in jail than out of it, as those out in society are forced to conform. In fact, the play focuses on Henry's increasing sense of awakening in terms of how he wishes to live his life and how activism is best used. Note Henry's rhetorical questions after Waldo does not turn up:
How do we make a sound? How do we break the silence?
For Henry, making the public stand of not paying his taxes is something that allows him to make the kind of sound that he desires to make, and breaking the silence of conformity, and so therefore it was the right thing for him to do.