ExxonMobil is only a business, yet for a century and a half it has vexed, baffled and unsettled us.

Take Hannibal Lecter, Daniel Plainview and Darth Vader, roll them into a single sinister character, and you start to grasp the feelings of generations of critics. But why? There are its outsized profits, of course – $41.1 billion last year alone – plus the remarkably enduring heartless persona of John D. Rockefeller, its founder in the old Standard Oil days.

But Gilded Age ruthlessness and success in the contemporary capitalist West do not sufficiently explain the shadow that ExxonMobil seems still to cast on our collective imagination. After all, today’s Apple is bigger than ExxonMobil, and the last of the robber barons have been dead for the better part of a century.

Enter a surprising and trenchant new decipherer of our confounded anxiety: Rex Tillerson, boss of the oil giant. Since becoming CEO six years ago, Tillerson has muddled the company’s traditional image with a polished and deliberate nuance that seems to project caring. He has been “cautious, genial, accommodating and eager to soften (the company’s) hard edges,” Steve Coll, the author of “Private Empire,” a new book on ExxonMobil, told me.

But recently, the mild-mannered, pin-striped executive seemed to abruptly throw caution to the wind. In a speech before the elite Council on Foreign Relations in New York, he suggested that Americans suck it up and adapt to global warming. “We have spent our entire existence adapting, OK? So we will adapt to this,” Tillerson said in reply to a question from the audience. “Changes to weather patterns that move crop production areas around – we’ll adapt to that. It’s an engineering problem, and it has engineering solutions.”

For starters, Tillerson said, ExxonMobil had set out to educate the “illiterate” public as to the facts, and move them away from the purveyors of “manufactured fear.”

At once, we are back to the Exxon we once knew.

What got into the “cautious” Tillerson is a question between him, his board and their shareholders. But conspiracy theories are unnecessary to explain the resulting nervousness of critics: As Coll’s book describes, Tillerson’s predecessor as CEO, Lee Raymond, declared war on efforts to restrain CO2 emissions, spending millions of dollars of company money starting in the late 1990s to fund writers and think tanks that cast doubt on climate science. The cash went directly from ExxonMobil’s public affairs unit and was channeled through the American Petroleum Institute, the industry’s lobbying arm in Washington, D.C., Coll writes, and it managed to help roil four decades of U.S. environmental politics.

ExxonMobil insists that there is no change in Tillerson or in company policy. Increasing CO2 emissions in the atmosphere are warming the planet, and the risks of this impact must be quantified, said Kenneth Cohen, ExxonMobil’s vice president for public and government affairs. Tillerson’s use of the word “adaptation” does not signal a policy shift, he said. As for Tillerson’s other language, he said, “Rex has a well-earned reputation for being straightforward and telling people exactly what he believes to be true after spending a lot of time thinking about it.”

Tillerson’s remarks also seem important in the context of the closely fought U.S. presidential campaign. Given ExxonMobil’s history of putting its lobbying might behind its deepest beliefs (and interests), the partial revival of Raymond’s overt hostility toward climate science seems notable. Tillerson may also be signaling, intentionally or not, a shot across the bow of President Obama’s green instincts. Tillerson and ExxonMobil appear to believe “there is no (political) cost to talking like this,” says Edward Chow, Chevron Corp.’s former head of international external affairs, now a senior fellow at the Center for Strategic and International Studies.

Three years ago, we saw a very different Rex Tillerson. In January 2009, the ExxonMobil CEO engineered a wholesale change in the company’s public policy. He abandoned his predecessor’s confrontational climate policy, declared ExxonMobil a believer in global warming, and said the company favored a tax on carbon as the best way to reduce emissions. Tillerson’s latest remarks seem to repudiate that switch.

But there appears to be more to it, according to Chow, who thinks it is a clue to ExxonMobil’s national electoral preference. “The same vanity displayed in the speech is in view here, saying ‘The country cannot in its right mind re-elect this guy.’ I can see them believing it,” Chow told me.

In an email exchange, Coll explained Tillerson’s shift as a reflection of an apparent transformation in industry fortunes. Until just a few months ago, major oil companies spoke mostly of a struggle to replenish the hydrocarbons that they drill every year, and the effort to keep their reserve base stable and growing. But a new North American oil boom, underpinned by a technological breakthrough in fracking, has appeared to improve the industry’s outlook.

According to Coll, these happier days have presented the industry with a new political risk – “resistance to fracking and evidence that global warming is getting worse.” In this scenario, Tillerson needs to beat down environmentalists if ExxonMobil is to succeed.