Former FBI Director James Comey's plain disdain for President Trump in his new book has a mirror image in his admiration for his predecessor, whom he lauds with compliments about his humor, leadership, and warmth.

If Comey and Trump got off on the wrong foot with an awkward conversation about uncorroborated charges Trump cavorted with prostitutes and viewed a golden shower, Comey's relations with Obama, who appointed him, remained positive.

'I was struck by the way he could see and evaluate a variety of angles on a complicated issue,' Comey says of the Columbia and Harvard Law-educated Obama.

'[He] displayed a sense of humor, insight, and an ability to connect with an audience, which I would later come to appreciate in the president even more,' he said, praising Obama's personal qualities and political skills,' he said.

President Barack Obama speaks with new FBI Director James Comey (R) during an installation ceremony at Federal Bureau of Investigation Headquarters in Washington, DC, October 28, 2013. Comey repeatedly praises Obama in his new book

'These are all qualities that are indispensable in good leaders.'

Comey added: 'He was an extraordinary listener, as good as any I've seen in leadership.'

Comey casts Obama as in command in the Oval Office, soliciting views but not necessarily favoring advice from the biggest of big wigs.

'In various meetings with the president, I watched him work hard to draw as many view points as possible into a conversation, frequently disregarding the hierarchy reflected in seating arrangements,' Comey said.

'He displayed a sense of humor, insight, and an ability to connect with an audience, which I would later come to appreciate in the president even more,' Comey wrote of President Obama

Fired FBI Director James Comey takes down President Trump in his new book, calling him 'unethical' and 'untethered to truth'

Comey's book, which goes on sale Tuesday, excoriates President Trump and is likely to be a best-seller

'He really did believe that he, Barack Obama, could always figure out the hardest stuff.'

He concludes: 'I had developed great respect for him as a leader and a person.'

According to Comey, Obama even cut him slack on one of the most controversial decisions of his tenure: how he handled the decision to announce the decision not to prosecute Hillary Clinton – an action many Democrats say cost Clinton the election.

'I picked you to be FBI director because of your integrity and your ability,' Obama told him in the Oval Office after the election, Comey writes.

'I want you to know that nothing – nothing – has happened in the last year to change my view.'

Comey wrote he was close to tears. 'Boy, were those words I needed to hear . . . I'm just trying to do the right thing,' he told the president, who responded: 'I know. I know.'

Comey's new book, 'A Higher Loyalty,' comes out Tuesday.

'I was struck by the way he could see and evaluate a variety of angles on a complicated issue,' Comey says of President Barack Obama

I SWEAR: Comey says Obama was 'an extraordinary listener, as good as any I've seen in leadership

Obama nominated Comey to succeed Robert Mueller as FBI Director. Trump fired him after Comey says Trump asked him to say he wasn't a target of the Russia probe

Comey offers no such praise of integrity or intellect when it comes to the man who fired him, after setting up what Comey describes as a mob-like loyalty test that Comey failed.

'I see no evidence that a lie ever caused Trump pain, or that he ever recoiled from causing another person pain, which is sad and frightening,' Comey writes.

'This president is unethical, and untethered to truth and institutional values. His leadership is transactional, ego driven, and about personal loyalty.'

He told ABC in an interview promoting the book he didn't know if unverified golden showers episode involving Trump in the Steele Dossier is true

As an example, he writes that Trump used physical space to intimidate him, whereas Obama and George W. Bush tried to make him feel at home with comfy chairs and fireside chats.

'In dozens of meetings in that space with Presidents Bush and Obama, I cannot recall ever seeing them stationed at their desk. They instead sat in an armchair by the fireplace and held meetings in a more open, casual arrangement,' Comey writes.

'That made sense to me. As hard as it is to get people to relax and open up with a president, the chances are much better in the sitting area, where we can pretend we are friends gathered around a coffee table. There, the president can try to be one of a group, and draw the others out to tell him the truth.'

He accounted Trump's set up behind his desk to a virtual throne.

'But when the president sits on a throne, protected by a large wooden obstacle, as Trump routinely did in my interactions with him, the formality of the Oval Office is magnified and the chances of getting the full truth plummet,' he writes.

Describing one such incident, he writes: '[S]itting at the desk once used by Presidents Kennedy and Reagan, he launched into one of his rapid-fire, stream-of-consciousness monologues.'