This uncertainty, it turns out, is central to how so much contemporary misinformation works. O’Connor and Weatherall make a distinction between absolute certainty and the confidence necessary to make informed decisions. “The worry that we can never gain complete certainty about matters of fact is irrelevant,” they write — though it comes up again and again in “The Misinformation Age,” as they show how industrial interests have repeatedly exploited any whiff of uncertainty to argue against government regulation.

The book contains useful summaries of the debates in the 1980s around the ozone layer and acid rain. Drawing from the research of Naomi Oreskes and Erik Conway in “Merchants of Doubt” (2010), O’Connor and Weatherall compare industry-sponsored campaigns questioning environmental damage to the strategic skepticism of tobacco companies, which disputed the link between smoking and lung cancer by insisting that the link wasn’t utterly definitive. As one tobacco executive put it, “Doubt is our product since it is the best means of competing with the ‘body of fact’ that exists in the mind of the public.”

The debate — or as the authors might put it, “debate” — around climate change has followed a similar narrative. O’Connor and Weatherall point out that the scientific consensus has long coalesced around human-caused climate change, even if denialists insist that the science is still unsettled.

The one thing you begin to notice in this book is that propagating a reflexive skepticism and sowing discord aren’t terribly difficult, especially when there’s a vested interest willing to pay for it; “merely creating the appearance of controversy” is often all that needs to be done.

Latour’s “Down to Earth” is a wilder, more playful book — even if, like “The Misinformation Age,” it covers big subjects like truth and the fate of the species. The election of Donald Trump, Latour says, was a clarifying event, not only for Americans but for the world. Here, finally, was a political figure whose brazen repudiations of reality laid bare what Latour has been saying all along — that a complacent faith in the ability of facts to speak for themselves was what rendered them vulnerable to Trumpian renunciation in the first place.

Image Bruno Latour Credit... Christopher Anderson/Magnum, for The New York Times

Latour’s talk about how facts derive their authority from trust might sound squishy and abstract, but he considers himself a realist. He says that climate change renders the old dichotomy of the global versus the local completely futile. Trump and the “obscurantist elites” who enable him are nurturing an “Out-of-This-World” fantasy by unleashing an aggressive despoliation of the earth that ultimately rejects the world they claim to inhabit. At the same time, Trump pacifies his base with panicky nationalism and border walls, delineating a “rump territory” that is “no more plausible, no more livable” than the globalized world they rail against.