BAR HARBOR — Arthur Caplan unabashedly calls himself a prophet.

As head of the Center for Bioethics at the University of Pennsylvania, Caplan has learned how to drag scientifically complex, ethically thorny issues such as gene therapy and cloning out of the laboratory and into the living room.

“I have no interest in being the ayatollah or the pope,” he said in a telephone interview from the sales floor of L.L. Bean in Freeport late Monday. “My job is to tell people what’s coming. Not to be the expert, but to be the prophet.”

It’s just this sort of comment that leads critics to describe America’s reigning bioethics guru as a “windbag.”

With a glib tongue and a quick sound bite, Caplan is the undisputed go-to man when U.S. media need an authoritative voice on the ethical implications of today’s scientific developments.

He has had a prodigious public career, including interviews by Time magazine and National Public Radio, appearances on ABC’s “Nightline,” more than 475 published articles, a regular column for King Features Syndicate and at least one book per year during the past decade. It has earned Caplan a following that would make any political candidate salivate.

But the man who earned a master’s degree in genetics and a doctorate in psychology isn’t satisfied with a superficial understanding of how genetic breakthroughs will change American life.

“Genetics will be to the 21st century what physics was to the 20th,” Caplan said. “With biological warfare, new drugs, genetically engineered foods, it will touch every aspect of our lives. But people know nothing about it — and I’m worried about that.”

Caplan will bring his message to Mount Desert Island when he speaks at 8 tonight at College of the Atlantic’s Gates Auditorium in Bar Harbor. Caplan is the school’s 2000 Leonard Silk Lecturer, invited to present an issue of scientific significance to the Mount Desert Island community.

Caplan hopes that by raising ethical questions at forums like tonight’s lecture, he can prod an ill-informed public to take a deeper interest in biological developments; and in doing so encourage society’s gatekeepers — schools, religious leaders and the media — to give Middle America a complete education in genetics starting from the ground up.

“Let me tell you a story,” he said. “Not too long ago, I was talking to people from the Hearst organization — middle and upper management — and I showed them a picture of a double helix, used to illustrate genetic engineering in one of their newspapers. I asked them where that little double helix was in their bodies — and they had no idea.”

Caplan gives the textbook definition of bioethics: “a field that examines ethical problems in medicine and the biological sciences.” But it didn’t even exist until the 1970s. The medical advances that led to organ transplants and the birth of “test-tube” baby Louise Brown opened a Pandora’s box of ethical questions that can’t be sifted neatly into right and wrong.

Today, as scientists at the Human Genome Project complete their map of the genetic code that’s buried in every human cell, giving a name and a home to each trait that makes a person unique, the questions are coming at lightning speed.

Caplan has a full-time staff of research associates in Philadelphia dedicated to combing the World Wide Web for developments. More than 50 people work under Caplan at the Center for Bioethics. But it’s ultimately the public that must pass judgment on whether to permit scientists to test every American’s genes for errors, and altering the genetic sequences that nature designed to “fix” imperfections (known as gene therapy).

“Americans aren’t going to turn decisions over to some ethics guru,” Caplan said. “We’ve got to depend on democracy, and that’s scary some days.”

Today, scientists can perform genetic tests to determine whether a person is at risk for such problems as cystic fibrosis. In five to 10 years, a hereditary predisposition to breast cancer, Alzheimer’s disease or even depression may be visible with a genetic scan of any human cell that is available in a single hair or a drop of saliva, he said.

Who should break the news to a patient? Will patients at risk for mental illness find the predictions becoming self-fulfilling prophesies? Who should have access to test results? Would terminating an employee because she has a strong genetic tendency for heart disease violate her civil rights? If an embryo’s genes test positive for Down syndrome, is abortion a medically responsible option? Is it fair to charge higher prices for drugs designed to work on people with rare genetic makeups?

Few Americans muse such weighty questions over their morning coffee.

Caplan fears the commotion over genetically engineered crops will be replicated as Americans face a brave new world of genetics with incomplete information. People are afraid of “Frankenfoods” but think nothing of the chemicals and pesticides applied on today’s industrial farms, he said.

“I think the irony of this is, in a couple of years GE food will actually be better for you,” Caplan said, citing the pharmaceutical and nutritional benefits of GE crops like Ingo Potrykus’s beta-carotene-enriched “golden rice.”

Forays into gene therapy have involved the experimental treatment program at the University of Pennsylvania’s Institute for Human Gene Therapy, which was blamed for the death of 18-year-old patient Jesse Gelsinger last year. That death raised fears that the medical community is charging forward with genetic research, whatever the cost.

“The death was tragic, but I’m a little bit sad that it set back progress in the area of gene therapy,” said Caplan, who came under fire for his role in selecting Gelsinger for the study. But the bioethicist’s view of genetic manipulation hasn’t changed. “I always thought this was ethically experimental. It’s tricky to get the genes to go where you want them to.”

The Food and Drug Administration shut down the University of Pennsylvania’s gene therapy program in January, but whether genetic experiments on human subjects will continue is a decision for the American people, Caplan said.

The prophet speaks with authority about his view of the future: I’d teach genetics in the schools. Sunday schools and synagogues need to struggle with these issues. Congresses and state legislatures need to be educated. And I’d have more media coverage across the board,” he said.

“And then,” Caplan said, “I’d cross my fingers.”