One person's right to free expression can damage another person's right to dignity, to freedom from harassment and violence and even to freedom of speech.
This dilemma was at the heart of the paper delivered by the President, Mrs McAleese, to The Irish Times/Harvard University Colloquium on Friday night.
Orange parades through nationalist areas, Nazi marches through Jewish villages in the United States and the burning of crosses in black people's gardens were all examples of free expression, she said. But all too were examples of how the exercise of this right to free expression hurt and sometimes silenced the victims of such gestures.
The President gave her address, followed by a 30-minute question-and-answer session, at the John F. Kennedy School of Government at the university. Her audience of 750 included diplomats, academics, students, journalists and members of the Irish-American community.
Mrs McAleese asserted both that the right to free speech was not absolute, and that victims of others' free expression must be given the means to talk back. She pointed to striking similarities in the assertions of the right to free speech contained in Article 19 of the UN Declaration of Human Rights, Article 40 of the Irish Constitution and the First Amendment to the US constitution.
But underlying her speech was a recognition of differences in how the US and European states tended to interpret the right to free expression. In the United States, she said, all sorts of racist and sexist expression could be defended on the ground of the First Amendment right to free speech. In Europe, her paper implied, there was a greater awareness of how such free expression could impact on other rights of individuals and victimise them.
Freedom of speech was not simply about words, she said, "but images, symbols, and even demonstrations or marches through which views and conviction are expressed or cultural heritage showcased."
The Irish example of freedom of expression that was perceived as hurtful and offensive by others was the controversy over Orange parades, particularly that from Drumcree Church down Garvaghy Road through a nationalist area and into Portadown.
Aware of the predominance of American academics and students in her audience, she gave two parallel US examples. A group of racist whites planted a burning cross - the symbol of racist persecution - in the grounds of the home of the Jones family, a black family living in a white area of St Paul, Minnesota, in 1992.
The US Supreme Court upheld the rights of the man charged with carrying out this act to do so under the First Amendment, which guarantees freedom of expression.
Similarly, in 1977, the American Civil Liberties Union supported on first amendment grounds the rights of a Nazi group to march through the mainly Jewish town of Skokie, Illinois.
In such cases, said Mrs McAleese, those demanding the right to freedom of expression were not simply seeking to express a point of view. In the Skokie case, for example, "they were not simply planning on marching any old place, they were on a mission - out to destroy peace of mind in a Jewish community." Similarly in Northern Ireland, some Orange parades were seen not simply as a cultural expression, "not simply as a major intrusion on their right to live peacefully in their own homes but as an assertion of superiority and an expression of a continued reluctance to accept the full equality of the two communities."
Perhaps her central point was that those who regard themselves as adversely affected by such assertions of the right to free speech must not only be entitled to talk back, but be afforded means and opportunities of talking back - "the kind of talk-back which ensures that free speech is not just a licence for the voluble bully".
Ensuring that those who feel wounded by hateful expression have an effective means of being heard and remedying harm done to them by those words would actually enhance the right to free speech, she said. It would be preferable to hedging and over-qualifying the right to free speech.
Having raised the questions, she did not give definitive answers. Should the Orangemen be allowed to march down Garvaghy Road? After all, the nationalist population has extensive freedom to talk back. It has articulate spokespersons and a national and international media that allows it speak clearly to Ireland and the world. Orange marches do not silence them. Yet they clearly oppose the Orangemen's right to march - a right which would almost certainly be seen as a basic First Amendment right in the US.
She acknowledged the irony in the nationalist position, observing that the history of the debate concerning freedom of expression in the North was full of such ironies. "Northern Irish Catholics, who were themselves beneficiaries of a civil rights movement which staunchly asserted its right to march, now find themselves challenging the right of the Protestant Orange Order to march where it pleases."
As she made clear in the question and answer session, she is not a politician and does not take sides in matters of current political controversy. However, she also made it clear she was not an absolutist when it came to defending freedom of expression.
"In this country [the US] obscenity is prohibited and indecency circumscribed. There are remedies for libel and sexual harassment. Also `fighting words' which are likely to make the person to whom they are addressed commit an act of violence are inhibited."
Similarly, the UN Declaration of Human Rights said the right to free speech was balanced by other obligations, including "the just requirements of morality, public order and the general welfare in a democratic society".
The issue was therefore not if it is wise to limit freedom of expression in certain circumstances, as such limitations were widely acceptable.
She proposed three means in which the right to freedom of expression could be enhanced "so that potential victims of speech and imagery are protected and given a remedy, even if that remedy is simply a credible and meaningful opportunity to talk back".
Firstly, education could teach people new ways of expressing cultural identity and could promote cross-community understanding. Secondly, research into the impact of words and images would allow greater understanding of the impact of some forms of free expression on people. Thirdly, providing places of communication or protest or "public talkback venues" would give people victimised by the free expression of others an opportunity to put their view across.
While never defining the actual boundaries beyond which free speech should not be allowed go, she ended with a statement of the principle underlying her paper. "By all means let us say to the hard of heart - you are free to speak, but you will never have the last word."