The true rule, in determining to embrace, or reject any thing, is not whether it have any evil in it; but whether it have more of evil, than of good.

Lincoln frames moral and practical judgment as comparative rather than absolute. Few policies, institutions, or personal choices are free of “evil” (harm, cost, injustice, unintended consequences). The “true rule” is to weigh whether the harms outweigh the benefits—an early statement of prudential ethics that resists purism and perfectionism. Read politically, it suggests a statesman’s mindset: reform and governance often require choosing the least bad option or accepting mixed outcomes to secure a greater good. The line also implies responsibility: one must actively measure and discriminate, not merely condemn something for containing any flaw.