In Homer’s Odyssey, Ulysses and his men had to sail by an island where the mythical Sirens lived. The Sirens’ voices were so beguiling they would lure passing sailors to shipwreck on the island’s rocky cliffs. Forewarned and intrigued, Ulysses had his men fill their ears with wax so they could not hear the songs, but he had himself tied to the mast of the ship so that he could hear the music but not steer the ship toward the island. The precaution worked.

The framers of the U.S. Constitution did something similar.

Sept. 17 was Constitution Day – the day that the draft Constitution was signed by its framers in 1787. The commemoration highlights a unique and uniquely critical aspect of the Constitution – that it is a written document. This contrasted with the unwritten British Constitution.

The written-ness of the Constitution is so obvious that its significance might be easily overlooked, but it should not be.

First, a written constitution is an embodiment of the principle underlying the rule of law – that we have a “government of laws and not of men,” in the phrase John Adams popularized. When government officials are constrained by preexisting legal principles, they are less able to justify arbitrary pronouncements.

Imagine if written laws were replaced by general requirements like reasonableness or fairness. Those enforcing the law would be empowered to make all kinds of demands that would be difficult to rebut, since the standards would be subjective. A written standard provides a safer benchmark that an aggrieved citizen can point to in defending the legality of their own actions.

Under the U.S. Constitution, there is even a branch of government charged with safeguarding the integrity of the written Constitution and the laws made consistent with its provisions: the judiciary. It is carefully separated from the lawmaking and enforcement responsibilities of government so that governing power does not become too concentrated in any entity, and so they can ensure that the lawmaking and enforcement responsibilities are carried out in accordance with the law.

Second, a written constitution provided a tangible way for the governed to hold accountable those to whom it had delegated the power of making and enforcing laws. When “we the people” ratified the Constitution, the ratification included concessions to the new national government. That government could impose taxes and punish crime. Those concessions were, however, specifically described and limited in the Constitution so that their growth and abuse would be more difficult. The Constitution then requires those who hold office under the Constitution to promise to support its provisions – and it specifies how those who are not faithful to that trust can be removed. Additionally, regular elections and checks and balances bolster that protection.

Third, the written Constitution provides aspirations even when the actual practice of making, enforcing and applying laws falls short. As one example, the written First Amendment guarantee protecting the exercise of religious freedom was not always honored in the practice of the nation. But the ideal it articulated became the foundation of political legitimacy that could be invoked by those denied the promised protections. Eventually, as minority religions and others persistently sought to have their rights vindicated, the practice of the state and national governments began to adhere more closely to that standard. That process continues even today.

In a recent, widely publicized decision, a state governor announced that in response to a spate of violence, the state would no longer honor a specific constitutional guarantee. The state’s attorney general quickly expressed opposition to the edict because of its constitutional implications, and a federal judge issued an order preventing enforcement of the dictate.

Without clear, enumerated constitutional guarantees, the governor’s order (or other decisions on a range of issues) would have been much more difficult to quickly correct. The written Constitution, widely understood and respected, largely prevents these types of situations before they arise and allows for resolution when they do.

The written Constitution, then, is like the mast in the story of Ulysses. Knowing that there would be occasions when the temptation to ignore or suspend specific protections or expand government powers would be intense, the Framers created a mechanism for accountability that could restrain even popular sentiment when it exceeded the bounds essential to ordered liberty. Those constraints would not be absolute because the document could be amended, but that process would take time and require a widely shared consensus, which would be likely to defeat nearsighted, temporary moods.

That is a profound reason to be grateful for our written Constitution.