Take a look at this photograph taken by Thomas Hoepker from the Brooklyn waterfront on the morning of September 11, 2001. Take a really good look. What are the people saying and thinking as they look away from the burning World Trade Center towers? That it’s a lovely morning to go bike riding? That they’ll be inconvenienced because they’ll have to cancel their dinner reservations in Greenwich Village? That flying two passenger jetliners into twin 110-story buildings is no big deal?

When I first looked at the photograph, which I have published at my own blog on several 9/11 anniversaries, my takeaway was that these people probably were slackers more interested in their own self-centered lives and that their body language indicated that none of them had given much thought to the extraordinary events unfolding across the East River, let alone racing over to Manhattan to donate blood or otherwise help.

But as a photographer who has taken tens of thousands of images in war, peace and on other world travels, I came to believe that I was reading much too much into the photograph. In fact, I concluded that I didn’t have a clue as to what was going on.

That one should never read anything into a photograph is one of the big takeaways from Believing Is Seeing (Observations on the Mysteries of Photography), a recently published book by filmmaker Errol Morris. Each of its six chapters originally appeared at The New York Times‘ Opinionator blog as an essay on a photograph or groups of photographs.

This is not to say that the truth can’t be coaxed from photographs, which Morris does to fascinating effect in analyzing two slightly different photographs by Roger Fenton of a Crimean War landscape littered with cannonballs, the infamous Abu Ghraib images, Depression-era photographs by Walker Evans and Arthur Rothstein, pictures of children’s toys lying amidst rubble after 2006 Israeli airstrikes on southern Lebanon, and an ambrotype photograph of three young children that was found clutched in the hand of a dead Union soldier at Gettysburg in 1863.

There have been a good many books that tread the same path as does Morris, but where Believing Is Seeing parts company with them is that Morris muses on where in a photograph does the truth lie? And is the truth altered if a photograph is posed — that is if Fenton had his assistant rearrange cannonballs for more dramatic effect in the second of his two famous photographs to make war seem even more horrible by making the landscape look more dangerous and perhaps Fenton himself braver? Or was the more dramatic photograph actually taken first?

Morris eventually solves the mystery of which photograph came first and the solution is so obvious that I wondered why I had not happened upon it 30 pages earlier. But I hadn’t figured it out because, like Morris, I front-loaded my perception of the photographs with preconceived notions that made eliminating possibilities much more difficult. The search for the truth, as Morris likes to call it, tends to eliminate the subtle and it only was when a very subtle aspect of the photographs was considered that the mystery was solved.

Among my best news photographs are those taken at the 1970 funeral of Yukio Mishima (left), the avant-garde Japanese author who died of ritual suicide after a failed coup d’etat against the Japanese army in an effort to restore the powers of the emperor. It would have never crossed my mind to ask his grieving family to move to the other side of the funeral hall because the light was better. (Sorry, I can’t locate any of these photographs.)

Morris, however, says he doesn’t care if one of Fenton’s photographs — or any photographs — were posed, and here I part company with him. (Incidentally, Morris blew an Oscar nomination for The Thin Blue Line in 1988 because he reportedly used staged re-creations, which were a violation of the Academy’s standards for documentary films.)

Posing family photographs and other non-photojournalist images are just fine with me.

There is nothing wrong with asking Uncle Leo to wipe the cranberry sauce from his upper lip when photographing a family reunion. And I would be ebullient if I could find a way to get our two dogs and three cats in the same frame without the cats looking in different directions and one of the dogs licking its backside. Perhaps gluing their paws to the floor would work. But as a photojournalist I never would sell the posed image to an agency with the claim that I just happened upon Jack, Nicky, Kimba, Taj and Iggie striking perfect poses.

Did Hoepker ask the people in his photograph to turn toward the camera and assume more relaxed poses because it would provide a more vivid contrast to what was happening across the river? I would be shocked if this famous member of Magnum Photos stable did so, and if photojournalists took a professional oath he would have violated it by manipulating the image beyond finding the best angle and perhaps waiting for the sun to be positioned just so.

Every war has iconic photographs and for the Iraq war none was more so than the image of a hooded prisoner at Abu Ghraib prison in Baghdad standing atop a cardboard box, attached to electrical wires with his arms stretched wide. The 2004 photograph, of course, became the indelible image of what I call the Bush Torture Regime.

When Ali Shalal Qaissi came forward two years later to say that he was the prisoner in the photograph it became famous all over again. The clincher to Qaissi’s claim was that he had a mangled hand and the man in the photograph appeared to have a mangled hand, earning him the nickname “Clawman.”

There was only one problem: Qaissi was not the man in the photograph taken by Sergeant Ivan Frederick.

As Morris points out, no one acknowledged the central role that photography itself played in the mistaken identification. Or as Morris puts it, “the way that photography lends itself to those errors and may even engender them.”

Part of the problem was that the photograph was low resolution and the deformed hand could not be clearly seen.

I share the view of Morris that it doesn’t matter that Qaissi was not the man in the photograph. After all, he was subject to similar abuse. Besides which, human rights workers needed a poster boy, so to speak, to dramatize the growing evidence of torture at Abu Ghraib and other U.S. military prisons.

No one except possibly Qaissi was involved in conscious fraud, and for journalists he presented the opportunity to tell the “real” story behind a major scandal and an iconic photograph.

Incidentally, the real prisoner appears to have been Abdou Hussain Saad Faleh, whom guard Hydrue Joyner nicknamed “Gilligan” because he was skinny like the hooded man on the box while Qaissi was stocky. Joyner nicknamed all the prisoners because they were easier to identify than, for example, Detainee #18470, which Faleh was and Qaissi eventually acknowledged probably was the man in the photograph.

Morris cites the familiar gestalt image of the duck-rabbit.

“If we believe we see a rabbit, we see a rabbit. If we believe we see a duck, we see a duck,” he writes. “But the situation is even worse than the Gestalt psychologists imagined. Our beliefs can completely defeat sensory evidence. If we believe that we see The Claw in the photograph, then we see The Claw in the photograph.”

This brings us to the controversies that attended a series of photographs of children’s toys lying in the ruins of an apartment block in Tyre, southern Lebanon after an Israeli air strike on August 7, 2006. The best known of these images (below, left) was taken by Ben Curtis of The Associated Press.

Morris says that the sheer number of photographs of other toys taken in the rubble, published in a post at slublog.com, suggests that some of the images were staged, and Israel’s sycophantic friends were quick to cry foul, the photographs coming as they did only a few days after it was revealed that a Reuters photographer had photoshopped a second Israeli F-16 flying over smoke covering the Beirut skyline. The allegations about the photographs with the toys were never proven.

“But the picture of Mickey Mouse is powerful because it is vague,” Morris writes. “It’s vagueness allows us to imagine all kinds of diverse scenarios, depending on our political sensibilities. It’s one of the things that’s fascinating about photography; photographs are both specific and vague.”

My knee-jerk reaction as someone with Jewish blood who nevertheless deplores the thuggery of the Netanyahu regime was that the Mickey Mouse photograph was not staged. It was an apt metaphor, even if perchance the toy belonged to the son or daughter of a Hezbollah soldier.

As should be obvious, I am passionate about photography and I am passionate about understanding the world that great photojournalists from Fenton to Hoepker have photographed. Morris is the same way, and his search for the truth ennobles the profession. (Unless, I repeat, images are posed.)

A casual reader might quibble with Morris’s repetitiveness, but that is what makes Believing Is Seeing such a great book. Like a police procedural in a murder mystery, that is how Morris eliminates possibility and finds the truth. At least some of the time.