Compassion, generosity, mercy, honesty, honor, loyalty, justice, friendship, and love. It is by these values by which people are able to cooperate and society is able to function.
One way to show a bad guy really Kick the Dog is to express his distaste for these virtues. It's not that he absolutely can't comprehend good; he understands exactly what goodness entails, and views it as an unnecessary burden that would hold him back and a weakness to be exploited in others. Though it is possible for the bad guy to share both of these tropes, in that the villain may not understand it at first, but later on, might scoff at such a concept with ridicule.
This is a very common subject when the Big Bad is confronted by the hero and tries to Break Them by Talking. It's also common for the villain to give a short speech about this when the hero is confronted with the choice of killing the villain and refuses to kill him. The hero usually responds by it is from good where his strength comes and that it's through the power of goodness that a diverse species as humans were able to succeed. Depending on where the work falls on the Sliding Scale of Idealism Versus Cynicism, the hero may be vindicated... or not.
Belief in this is a telltale sign of being The Sociopath, The Unfettered, or The Social Darwinist who sees empathy for others as a bad trait in favor of a literal struggle between life and death. This can be one of the Jerk Justifications for a character to be a Jerkass with a Lack of Empathy. The Unapologetic may justify themselves for not apologizing by believing that remorse makes a person weak. Someone who holds grudges and never accepts apologies sees forgiving someone as a sign of weakness. A lot of the time, this tends to be the rationalization of someone who thinks It's All About Me. Cynically interpreted, one who believes this can be seen as the Übermensch. This may also be invoked by an Anti-Hero to justify fighting dirty to win, by any means necessary.
For some explanation on why this view is wrong, see our analysis page.
See also Straw Nihilist, who believes that good is pointless rather than a weakness (though it's not uncommon for many villains to believe both). Supertrope to Love Is a Weakness. Contrast Evil Virtues, where evil displays virtues/morals in order to be effective. Compare and Contrast Good Is Not Soft and Beware the Nice Ones, in which a virtuous character actively demonstrates the (potentially fatal) error in this thinking.
