Decency is the immediate rightness of conduct given one's desires, as honesty is the immediate rightness of conduct given one's beliefs.
Decency does not guarantee justice, nor does honesty guarantee truth. Indeed, the pursuit of truth sometimes requires dishonesty, and the pursuit of justice sometimes requires indecency.
Science is the pursuit of truth, constrained by honesty, not decency.
Politics is the pursuit of justice, constrained by decency, not honesty.
Art is a scandal.