"Let your conscience be your guide," Jiminy Cricket told Pinocchio. Oddly, many Catholics have come to believe that these words are found in Scripture, or at least in the teachings of the Catholic Church. Even more oddly, not a few of them will cite the words of a cartoon cricket to justify entering a voting booth today and casting their ballot for candidates whose positions on such literally life-and-death issues as abortion and embryonic stem-cell research directly contradict Church teaching.
"In all he says and does," the Catechism of the Catholic Church declares, "man is obliged to follow faithfully what he knows to be just and right." That, in fact, is the operation of conscience. Conscience is not a feeling ("I like this candidate") nor a desire ("I want to vote for this candidate"), but the judgment by which "man perceives and recognizes the prescriptions of the divine law."
That is why the Church insists that our consciences must be well formed. "The education of conscience," the Catechism says, "is indispensable for human beings who are subjected to negative influences and tempted by sin to prefer their own judgment and to reject authoritative teachings."
If our conscience is poorly formed, we will make the wrong choices--and as Catholics, one way to tell if our conscience is poorly formed is to compare our choices to the teaching of the Church. "Freedom of conscience" does not mean that whatever choice we make is right; it means, as the Catechism notes, that we have the right "to make moral decisions."
When we make no effort to form our conscience properly and, as a result, make immoral decisions, we suffer the consequences of sin. It's something to keep in mind on Election Day, when it is so easy to convince ourselves that our choices have no bearing on our moral lives.