Question: What was the man whom Dr. Diarmuid Whelan wrote his doctoral thesis on?

full_context: Document 1: Conor Cruise O'Brien: Conor Cruise O'Brien (3 November 1917 – 18 December 2008) often nicknamed "The Cruiser", was an Irish politician, writer, historian and academic. His opinion on the role of Britain in Ireland and in Northern Ireland changed during the 1970s, in response to the outbreak of The Troubles. He saw opposing nationalist and unionist traditions as irreconcilable and switched from a nationalist to a unionist view of Irish politics and history. O'Brien's outlook was always radical and the positions he took were seldom orthodox. He summarised his position as intending "to administer an electric shock to the Irish psyche".
Document 2: Brendan Duddy: Brendan Duddy (10 June 1936 – 12 May 2017) was a businessman from Derry, Northern Ireland, who played a key role in the Northern Ireland peace process. A notable Catholic republican, who was a pacifist and firm believer in dialogue, Duddy became known by MI6 as "The Contact." In his book "Great Hatred; Little Room – Making Peace in Northern Ireland", Tony Blair's political advisor Jonathan Powell described Duddy as the "key" which led to discussions between republicans and MI6, and ultimately the Northern Ireland peace process.
Document 3: Dublin Institute for Advanced Studies: The Dublin Institute for Advanced Studies (DIAS) (Irish: "Institiúid Ard-Léinn Bhaile Átha Cliath" ) was established in 1940 by the then Taoiseach, Éamon de Valera under the "Institute for Advanced Studies Act, 1940" in Dublin, Ireland. The Institute consists of 3 schools: the School of Theoretical Physics, the School of Cosmic Physics and the School of Celtic studies. The directors of these schools are currently Professor Werner Nahm, Professor Luke Drury and Professor Liam Breatnach. The Institute under the act is empowered to "train students in methods of advanced research" but does not itself award degrees; graduate students working under the supervision of Institute researchers can, with the agreement of the governing board of the appropriate school, be registered for a higher degree in any university worldwide.
Document 4: Ruairí Ó Brádaigh: Ruairí Ó Brádaigh (] , born Peter Roger Casement Brady; 2 October 1932 – 5 June 2013) was an Irish republican revolutionary and political leader. He was Chief of Staff of the Irish Republican Army (IRA) from 1958 to 1959 and again from 1960 to 1962, president of Sinn Féin from 1970 to 1983, and president of Republican Sinn Féin from 1987 to 2009.
Document 5: Dervla Kirwan: Kirwan was born in Churchtown, Dublin, Ireland. Her father, Peter Kirwan, was an insurance broker, and her mother, Maureen O'Driscoll, was a language teacher. She is the youngest of three daughters. She attended Loreto Beaufort in Rathfarnham, Dublin, a Catholic school for girls, until the age of 16, when she was asked to leave as her career as an actress started to progress. Kirwan completed secondary school at the now-defunct non-denominational school Sandymount High School in Dublin.
Document 6: Diarmuid Whelan: Dr. Diarmuid Whelan (11 August 1971 – 1 June 2010) was an Irish academic in the history department of UCC. Born in Cork, he studied at Christian Brothers College, Cork and UCC. He wrote his doctoral thesis on Conor Cruise O'Brien.
Document 7: Diarmuid Johnson: Diarmuid Johnson (1965 -) is a writer. He was born in Cardiff (Wales), brought up in Galway (Ireland), and holds BA, MA and PhD degrees in Celtic Studies. He has published poetry and prose in Irish, Welsh and English. His literary activity extends to the field of translation, and he has authored or co-authored five works of Welsh literature in translation, two in Irish, one in English, one in French, and one in Romanian. He has also translated poetry from Romanian into English. Since 2004, he has published a book a year on average. These include, most recently, 'Conaire Mór - Seacht nDoras na Cinniúna' (2017), a retelling of the Old Irish epic 'Togail Bruidne Da Derga', being one of a planned series with Leabhar Breac; 'Pen and Plough - 20th Century Poets and Bards of Ceredigion (Carreg Gwalch, 2016); 'Rún na mBradán - Dánta Gaeilge 2005-2015 (Coiscéim, 2016). From 1989 to 1996, Diarmuid Johnson lectured in Celtic Studies in Britanny, Germany and Ireland. From 1996 until 2000, he worked as a journalist, scriptwriter and translator in Conamara. He was editor of "Cuisle", a monthly journal in Irish, between 1999 and 2000, and was editor of the trilingual online literary journal "Transcript" from 2002-2004. He worked at the Mercator Centre for Minority Languages at The University of Aberystwyth from 2002-2006. The years 2007-2013 he spent lecturing in Poland and Germany. In 2014, he was bard in residence with Menter Rhos-y-Gilwen in Pembrokeshire, Wales. He now works as a freelance writer and musician, contributes to Raidió na Gaeltachta and teaches Irish in Ireland in the summer. He has two daughters, is married, and divides his time between Ireland, Wales, and Brittany. He also has close ties with Germany, principally in the Rheinland area, where he has been performing and teaching since 2011.
Document 8: UCC Philosophical Society: The UCC Philosophical Society, Commonly known as "the Philosoph", is the largest debating society at University College Cork, Ireland. The Philosoph was founded in 1850, making it the oldest society at UCC. The Society carries out a number of functions, including weekly debates with high-profile guest speakers, participating in debating competitions, running workshops for the students of UCC to develop their public speaking skills and running debating competitions and workshops for schoolchildren (including the Denny Schools Debating Competition). In the 1960s Seán MacBride SC and Nobel Peace Prize winner called the Philosoph "the centre of independent thought in Ireland" when discussing the state of the nation. It has been a feature of scholarly life in Cork for generations.
Document 9: Joseph O'Connor: Joseph Victor O'Connor is an Irish novelist. His 2002 historical novel "Star of the Sea" was an international number one bestseller. Before success as an author he was a journalist with the "Sunday Tribune" newspaper and "Esquire magazine". He is a regular contributor to Raidió Teilifís Éireann (RTÉ). He is a member of the Irish artists' association Aosdána.
Document 10: Lelia Doolan: Doolan was born in Cork in 1934. She studied French and German at University College Dublin, where she won a scholarship to study at the Brecht Theatre in Germany.
Document 11: Fintan O'Toole: Fintan O'Toole (born 1958) is a columnist, literary editor and drama critic for "The Irish Times". He has written for the paper since 1988. O'Toole was drama critic for the "New York Daily News" from 1997 to 2001 and is a regular contributor to "The New York Review of Books". He is an author, literary critic, historical writer and political commentator, with generally left-wing views. His recent books have focused on the rise, fall and aftermath of Ireland's 'Celtic Tiger'. He has been a strong critic of political corruption in Ireland throughout his career.
Document 12: Fergus O'Hare: Fergus O'Hare (aka Fergus Ó hÍr) was involved in the civil rights movement in Northern Ireland as a member of People's Democracy in the late 1960s and early 1970s. Later he became a founding member and executive member of the Northern Resistance Movement, which continued to campaign for civil rights in Northern Ireland.
Document 13: Colum Kenny: Colum Kenny is an author and emeritus professor at Dublin City University (DCU), in Dublin, Ireland. Emeritus Professor, B.C.L., Barrister-at-Law, Ph.D. Columnist for the "Irish Times". Formerly chair of the Masters in Journalism programme at DCU. School of Communications faculty 1982-2015. Areas of special interest include media and culture, history and society. A member of the Broadcasting Authority of Ireland 2010-2015 and of the Broadcasting Commission of Ireland/IRTC 1998-2003. A former employee of RTE, he was a founding board member of the E.U. Media Desk in Ireland and is a council member of the Irish Legal History Society. He was a member of the Media Mergers Advisory Group that reported to the Minister for Enterprise, Trade and Employment in 2008. The author of many academic articles on cultural and media matters, he is also a member of the National Union of Journalists and a frequent contributor to media debates and a consultant on communications. Awarded the DCU President's Award for Research in the Humanities and Social Sciences, 2004/5.
Document 14: Terence O'Neill: Terence Marne O'Neill, Baron O'Neill of the Maine, PC (10 September 1914 – 12 June 1990) was the fourth Prime Minister of Northern Ireland and leader (1963–1969) of the Ulster Unionist Party (UUP). A moderate unionist, who sought to reconcile the sectarian divisions in Northern Ireland society, he was Member of the Parliament of Northern Ireland for the Bannside constituency from 1946 until his forced resignation in April 1969 as communal conflict erupted; his successor in Parliament was Ian Paisley, while control of the UUP also passed to more hard-line elements.
Document 15: Brian O'Nolan: Brian O'Nolan (Irish: "Brian Ó Nualláin" ; 5 October 1911 – 1 April 1966) was an Irish novelist, playwright and satirist, considered a major figure in twentieth century Irish literature. Born in Strabane, County Tyrone, he is regarded as a key figure in postmodern literature. His English language novels, such as "At Swim-Two-Birds", and "The Third Policeman", were written under the "pen name" Flann O'Brien. His many satirical columns in "The Irish Times" and an Irish language novel "An Béal Bocht" were written under the name Myles na gCopaleen.
ground_truth: an Irish politician