Caught in the middle now is the next son, who is trying to accomplish what no family has done in American history with a third Bush administration.

Those who have worked for either of the two presidents strongly testify to their deep love and scoff at what they call overwrought Oedipal theories of rivalry and resentment. Just last year, George W. Bush published his own biography of his father, venerating him in loving terms. The elder George Bush has often bristled at criticism of his son. Both men hate being “put on the couch,” to use a phrase each one employs.

Yet few who know them well would assert that they see the world exactly the same way. The younger, brasher and more conservative George W. Bush has made clear that he shaped some of his policies in the White House based on the lessons of what he saw as his father’s mistakes. Friends of the older, more genteel and moderate President Bush have often said he was deeply uncomfortable with the more hawkish elements of his son’s administration.

In the new book, the first President Bush expresses his love and support for his son and sticks by his decisions to go to war in Iraq and remove Saddam Hussein from power. But he gently chides his son for “hot rhetoric” like his “axis of evil” speech, and says that the real responsibility for the way Mr. Cheney and Mr. Rumsfeld operated belonged to the president. “The buck stops there,” he said.

What was so surprising about the comments was not their sentiment, but rather that the older Mr. Bush would express them in public. When Mr. Meacham went back to show him a transcript of his remarks and ask if he wanted to clarify, the ex-president took none of it back. “That’s what I said,” he told Mr. Meacham.

The remarks reflect a long history with both Mr. Cheney and Mr. Rumsfeld. The elder Mr. Bush and Mr. Rumsfeld were rivals going back to the 1970s, and although Mr. Cheney served as his defense secretary, Mr. Bush told Mr. Meacham that Mr. Cheney had changed as vice president.