In "The Lady, or the Tiger?" the theme of justice is explored through the king's arbitrary and whimsical method of trial. The king's system relies on chance rather than evidence, reflecting his "semi-barbaric" nature. Justice is portrayed as a spectacle, devoid of fairness and reason. The story questions the true nature of justice, leaving readers to ponder the moral implications of the king's decisions.

The king's method of administering justice involves a public trial where the accused must choose between two doors. Behind one door is a lady, symbolizing innocence and reward, while behind the other is a ferocious tiger, symbolizing guilt and punishment. This method relies on chance rather than evidence and reflects the king's arbitrary and whimsical sense of justice. The king's arena, built for administering "poetic justice," is a place where crime is punished and innocence rewarded by "the decrees of an impartial and incorruptible chance." In reality, there is merely chance, not justice.

The public arena symbolizes what the king believes is the fair, impartial administration of justice. The king is notably described in the story as "semi-barbaric," which means that, though a brutal tyrant, he's anxious to be perceived as adhering to at least some civilized norms. Making the arena a public place is one way of doing this. Instead of being killed in some dark torture chamber, the princess's suitor will meet his fate in public, where everyone can see for themselves that justice has been done. In reality, however, the cruelty of this semi-barbaric king is never far away; it lurks menacingly behind one of the doors in the shape of a vicious, man-eating tiger. This shows us that the public arena is merely a cynical way of concealing barbarism beneath a thin veneer of civilization.

The king's system of justice is "perfect" because only destiny and chance determine the fate of a person accused. It eliminates any kind of bias or prejudice, which could sway a jury or a judge toward mercy or severity depending on their personal feelings toward the accused. The king's version of justice does not allow for that kind of personal involvement in a case, which gives the king reason to believe it is perfect. However, this system does not consider the honesty of the accuser or any extenuating circumstances that might explain the accused's crime. As well, chance and destiny ignore the belief in a person's free will, which might be problematic to some readers.

...if the accused person opened the other door, there came forth from it a lady, the most suitable to his years and station that his majesty could select among his fair subjects, and to this lady he was immediately married, as a reward of his innocence. It mattered not that he might already possess a wife and family, or that his affections might be engaged upon an object of his own selection; the king allowed no such subordinate arrangements to interfere with his great scheme of retribution and reward.

The king's justice is not true justice. It is a spectacle, a game of chance that disregards the individual's circumstances and humanity. The story leaves readers questioning the fairness of such a system and the true nature of justice itself.