Story highlights Dean Obeidallah: President Obama will take presidential oath with his left hand on two Bibles

Obeidallah: Presidents swear to uphold the Constitution, so why not use that document?

The Constitution doesn't mention a Bible, he says, and two presidents didn't use one

Obeidallah: John Quincy Adams swore on a book of laws, emphasizing his first loyalty

U.S. presidents should not be sworn into office with their hand on a Bible.

At Monday's inauguration of his second term, President Barack Obama will raise his right hand and place his left on not one , but two Bibles : One owned by Abraham Lincoln and the other by Martin Luther King Jr.

The Constitution requires he give this oath of office: "I do solemnly swear (or affirm) that I will faithfully execute the office of President of the United States, and will to the best of my ability preserve, protect, and defend the Constitution of the United States."

Dean Obeidallah

You might recall that at his 2009 inauguration, President-elect Obama and Chief Justice John Roberts played some kind of "mad libs" with this oath during the swearing-in ceremony, muddling it so badly that they had to redo it a few days later. But why does the president swear on a Bible? Why doesn't he place his hand on the U.S. Constitution -- the very document he's promising to "preserve, protect and defend"?

The Constitution does not require that the president take the oath of office by swearing on a Bible. That would have been a very simple requirement for the constitutional drafters to include. To the contrary, the Founders wanted to ensure that Americans of any faith -- or no faith -- could hold federal office.

They set it forth plainly in Article VI: "... No religious test shall ever be required as a qualification to any office or public trust under the United States."

Placing a hand on a Bible while reciting the presidential oath is simply a tradition started by George Washington. Indeed, two presidents, Teddy Roosevelt and John Quincy Adams, did not use a Bible at their swearing-in ceremonies.

Although Roosevelt's reasons are unclear, John Quincy Adams' reasons could not be more plain.

Adams, the son of President John Adams, was a religious man. But he chose to be sworn in with his hand on a book of U.S. laws. He wanted to demonstrate that he recognized a barrier between church and state and that his loyalty was to our nation's laws above all else.

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Adams also refused to campaign for the presidency because he believed it was beneath the dignity of the office to make promises that might not be kept. Clearly, Adams was not a man who acted because of tradition alone. He had to truly believe in what he did.

Some will argue that swearing on the Bible ensures the president adheres to his oath. But let's be honest: We have seen presidents and other elected officials swear to uphold the laws of our country with their hands on a Bible and go on to break many laws and ethical rules. It comes down to the person's moral code, not a 30-second oath.

And just so it's clear, my objection is not only to the Bible. I would hold the identical view if it were the Quran, the Book of Mormon or any other religious scripture.

The Founding Fathers made it clear that the U.S. Constitution, "...shall be the supreme law of the land." It is the living legacy they bestowed upon us. It is the framework for our government. And as such, that's the document our president should place his hand on.

It should be clear to all that the president views the Constitution as our nation's genesis.

Editor's note: Join Dean Obeidallah for a live discussion from 1:30 to 2:30 p.m. ET Thursday about taking the oath of office on a Bible. He will respond to your thoughts in the comments section below. Have questions for him? Ask in advance by posting a comment.