America's democratic values - the marvelous freedoms that have characterized the nation - rest largely on thepillar of privacy protection.
Yet today, the historic coincidence of post-9/11 terrorist fears and remarkable technological advances in the area of security and data gathering threaten to undermine that privacy pillar.
A comment during a recent lunch captured for me the essence of society's current privacy predicament, and the great post-9/11 national privacy conundrum. "You know," said my lunch companion, a professor, "researchers who scan brains have found that separate portions light up if you're feeling love in a committed relationship, lust, or romantic love."
Whether this is true or not, simply musing about the scientific possibility of seeing into our innermost thoughts and feelings sheds light on how Americans are trying to figure out the amount and kinds of privacy they need, and what they are willing to sacrifice for collective safety. Will Americans be safe only if technology allows them to see into the recesses of each other's hearts and minds?
Privacy - as Americans know it today - is a fairly recent concept and experience. The historian Philip Aries has written that "until the end of the 17th century, nobody was ever left alone." Only a few eccentric hermits hid out in caves. Indeed, in the Puritan colony of Connecticut, no one was allowed to live alone for fear that it would challenge communal life, and make the solitary soul easy prey for the devil.
But over time, ideas changed. The national feeling today comes much closer to the ideal put forth by the Transcendentalist writer Bronson Alcott: "Individuals are sacred. The world, the state, the church, the school, all are felons whenever they violate the sanctity of the human heart."
America has come to value privacy deeply because it is understood that the right of privacy not only allows the freedom of solitude, but it also shields social interaction - from intimate to more open associations in which people can do and say heartfelt and spontaneous things with others that they wouldn't feel free to do or say if outsiders were watching.
Americans have long cherished the "right to be let alone" because they know privacy underpins liberty, choice, self-expression, creativity, and autonomy. Inventors, entrepreneurs, tinkerers, and artists alike grasp that their creative processes rest on not feeling prematurely scrutinized, not having to go public until they're ready.
Totalitarian governments consider privacy extremely dangerous. Indeed, a hallmark of such governments - Stalinist Russia, East Germany, Communist China - is the amount of spying they do on their own citizens and have their citizens do on each other. Leaders of such systems understand that, under surveillance, people are less assertive and more worried, careful, and vigilant. It can make them shrink into themselves so that they become smaller, meeker, and less inclined to stand up for their human rights.
Describing her own experiences and those of her poet husband under the continual hostile surveillance of Stalinism, Nadezhda Mandelstam wrote: "We all became slightly unbalanced mentally - not exactly ill, but not normal either: suspicious, mendacious, confused and inhibited in our speech.... What value can such people have as witnesses?"
Privacy is a precious, fragile concept. In the right measure, it shields and nurtures humanity; it enables the development of "the self," the emboldened human creature with a distinctive voice and talents.
However, life is never simple. Some people - perhaps all of us to varying degrees - have the potential to exploit privacy by using it to shield secret antisocial or illegal things they do. A certain amount of communal or technological surveillance makes society safe and functional. If everyone believed that "no one is watching," too many of us might stop paying taxes or start running traffic lights, pilfering goods, or mugging the guy blocking our path. Excessive anonymity becomes alienation and anomie.
Yet the amount and kind of social and legal surveillance good for a society is an extremely delicate matter. Too much and you shut down creativity, liberty, and initiative; you diminish human dignity. Too little, and you may elevate collective anxiety and danger.
Terrorism has complicated matters. Or, to put it more precisely, terrorist attacks in our highly mobile, anonymous, heterogeneous, technologically sophisticated society have tipped our current privacy balance in worrisome ways.
The 9/11 attacks frightened Americans and made them warier of strangers. Humans, to survive, are wired with stranger anxiety; all of us wonder how much to trust someone we don't know well. A fundamental human question, perhaps "the" question, is whether a stranger will do us harm. "Is the man in the next seat in the plane carrying a bomb?" "Is the woman I met in the Internet chat room as kind as she seems, or is she (or is it a he?) going to somehow exploit and hurt me?"
Frankly, we can't distinguish terrorists from anyone else on sight - whether the public kind who carry grenades, or the private kind who make intimacy miserable (like domestic abusers who use the shield of marital privacy to hide their violence). We often don't know until it's too late.
Americans, loving technology as they do, have responded to their elevated fear with machines that reduce privacy in the hope of creating safety through omniscience. Not all of this technology is new - but the 9/11-inspired acceleration of its development and availability is new.
Fingerprint, face, and iris recognition scanners are being rushed into service. Citizens are being encouraged to report on their neighbors. Researchers at MIT are working on brain scans that potentially might be able to "see" when you're lying. Defense contractors have manufactured machines that "see" through thick concrete walls. Entrepreneurs are developing electronic chips you can implant in your children - just as you can do with pets - so you'll always "see" where they are.
And private companies and government agencies are collecting endless gigabytes of data on diverse aspects of citizens' health, finances, and habits - much of it for sale. "Antiterrorist" subagencies within the government continue to pursue ways of acquiring that data to help "search" for terrorists.
And now, my lunch companion suggests that the quest for security may also be exploring ways to see into the deepest secrets of the heart. This notion captures a collective anxiety in a single image: What if the enthusiasm for safety through technology destroys the privacy of the human heart?
Ingenuity and fear seem to be spinning into an alliance that is altering the world faster than can be grasped, much less assessed. Will machines and antiterrorist efforts protect us, or will they lead to an unintended "virtual" totalitarianism where everyone feels watched all the time - where humanity is diminished? Are there risks worth taking to protect liberty? Or will the collective need to feel safer through more surveillance crush freedom?
These profound questions deserve careful attention. Vigorous oversight and "privacy impact" reviews of new antiterrorist laws, devices, and practices are essential.
In policy and practice, the US government needs to enforce more concretely America's collective commitment to privacy. Canada, for example, has a "privacy commissioner." Why doesn't the US?
Alleviating post-9/11 fear - and creating genuine security - should include allocating fewer resources to buying unproven machines and private data, and more to funding watchdog agencies - private and public - that keep abreast of the collective surveillance "cost" to our country.
Crisis offers America the opportunity to recommit to a fundamental democratic value. Let's not let fear stop us.
• Janna Malamud Smith, a clinical social worker, is the author of 'Private Matters: In Defense of the Personal Life.'