WASHINGTON — Flashback: Galileo is sitting under house arrest pondering the unyielding ignorance of The Church for refusing to consider his proposition that the Earth circled the sun, which, contrary to Scripture, was at the center of what we now call the solar system.

We find this historical anecdote preposterous today, but people were persecuted for lesser heresies in Galileo’s time. Though we are now centuries removed from such dim-wittery, we find ourselves in a not-dissimilar pickle.

After decades free of many crippling and deadly diseases thanks to the miracle of vaccines, some people are skeptical. Parents fearful of side effects, often on account of anecdotal evidence or discredited studies, are reluctant to vaccinate their children.

Marin County, California, a liberal enclave famous for its beauty and wealth, seems to be the epicenter of the debate. Many have opted out of vaccinations as part of their evolution into honeybees. Some see vaccines as a conspiracy of Big Pharma. Elsewhere, especially in the South, people are simply distrustful of authority, especially government.

The latter group is familiarly known as the GOP base. They tend to be litmus-test conservatives on social issues and place Scripture above science.

On the bright side, the far left and the far right finally have found common ground. They’d rather let their children risk illness — and their country an epidemic — than contaminate their offspring’s pristine bodies with antibodies.

One wonders what public tortures Jonas Salk might have encountered had he presented his polio vaccine today rather than in the 1950s. One crucial difference is that polio left visual reminders of its assault on the human body. The 1952 epidemic affected nearly 58,000 people, more than 3,100 of whom died and some 21,000 were left disabled.

Most Americans under the age of 50, including doctors, have never seen measles. Now, after decades of being a virtually measles-free nation, we have 100 cases spread across at least 14 states and the potential for more as stubborn purists resist common sense. Science and experience overwhelmingly support vaccines, and the single study to the contrary, suggesting a connection to autism, has been thoroughly discredited.

Naturally, into this tar pit, the GOP presidential field has fallen. Or rather, been pushed. Asked about the vaccine controversy, both New Jersey Gov. Chris Christie and Kentucky Sen. Rand Paul have handed the media a fresh bone to gnaw.

Christie initially said that parents “need to have some measure of choice,” though he later clarified by saying that children should be vaccinated against measles. Paul told radio host Laura Ingraham, “While I think it’s a good idea to take the vaccine, I think that’s a personal decision for individuals.”

Neither comment standing alone is objectionable. Barring a time-release patch from God, vaccines are the best we’ve got. Eventually, most parents come around to this conclusion, despite reluctance to inject their children with a tiny dose of the virus. They do it because the alternative is unthinkable.

While parents’ rights should always be protected in the absence of harm to their children, the public health of the nation also has to be protected. Individual rights are justifiably modified when the exercise of those rights adversely affects others. Smoking is a textbook example of this premise.

Preserving individual freedom is one of the compelling forces of modern conservatism and remains its most attractive feature. Thus, Republican candidates are faced with a daunting balancing act of confirming to primary voters their allegiance to the principle while also signaling to the rest of the country that they’re not that foolish.

These conundrums are not new. The conflict between individual rights and the greater good is the fundamental argument in a democracy, the success of which relies upon an educated rather than only radio-informed citizenry, as well as leaders willing to defend science over ideology.

Aspiring presidents would do well to articulate these conflicts with compassion, without condescension or pandering — while explaining why, in this case, vaccines are the right choice. For starters they might quote Thomas Frieden, director of the Centers for Disease Control and Prevention:

“Study after study has shown that there are no negative long-term consequences. And the more kids who are not vaccinated, the more they’re at risk and the more they put their neighbors’ kids at risk as well.”

There. That didn’t hurt much, did it?

Kathleen Parker is a columnist with the Washington Post Writers Group.