Ecclesiastical Faculties

TIONGCO, Fr. Isaias D., O.P., J.C.D.

Academic Degrees

Doctorate in Canon Law, 2001
Facultad de Derecho Canónico, Instituto Martin de Aspicueta, Universidad de Navarra, España

Licentiate in Canon Law, 1993
UST Faculty of Canon Law, Manila, Philippines 

Bachelor of Science in Commerce major in Accountancy, 1978
University of the Assumption, San Fernando, Pampanga

Bachelor of Arts in Philosophy, 1988
Philippine Dominican Center of Institutional Studies, Quezon City, Phils.

Bachelor of Sacred Theology, 1991
UST Faculty of Sacred Theology, Manila, Philippines 

Area of Specialization

Temporal Goods of the Church, Sanctions in the Church, Research and Thesis Writing, Special Procedures II (cc. 1717-1752), General Norms (cc. 01-95), Sources of Canon Law.

Published Work


TIONGCO, Isaias, O.P., “Reflections on the Past, Thoughts on the Future” in Boletin Eclesiastico de Filipinas, vol. LXXXVI, 876-877 (January-April, 2010), pp. 217-222; also in Canonews, The Official Student Newsletter of the Faculty of Canon Law, University of Santo Tomas, Manila, Philippines, (Second Semester A.Y. 2008-2009), pp. 10-12; also in The CLSP Gazette, vol. 13.22 (April 2009), pp. 10-11.

ACIN, Mayong Andreas, O.F.M. Cap. & TIONGCO, Isaias, O.P., “The Nature of Delict in Canon 1321: Its Implication on the Dismissal Process of Religious in Cases of Sexual Misconduct Part I,” in Philippiniana Sacra, Vol. XLV, No. 135 (September-December 2010), pp. 585-609.

TIONGCO, Isaias, O.P., “La Naturaleza de la Potestad en los Institutos Religiosos a la luz de las Codificaciones de 1917 y de 1983,” in Philippiniana Sacra, Vol. XLVI, No. 136 (January-April 2011), pp. 3-29.

ACIN, Mayong Andreas, O.F.M. Cap. & TIONGCO, Isaias, O.P., “The Nature of Delict in Canon 1321: Its Implications in the Dismissal Process of Religious in Cases of Sexual Misconduct Part II,” in Philippiniana Sacra, Vol. XLVI, No. 136 (January-April 2011), pp. 63-84.

KARAAN, Edward & TIONGCO, Isaias Antonio, O.P., The Catholic Church, Temporal Goods and Church-State Relations – Part One, in Philippiniana Sacra, vol. 47, no. 139, January-April 2012, pp. 43-66.

KARAAN, Edward & TIONGCO, Isaias Antonio, O.P., The Catholic Church, Temporal Goods and Church-State Relations – Part Two, in Philippiniana Sacra, vol. 47, no. 141, May-August 2012, pp. 657-706.


Book Reviews:

Carlos Jose Errazuriz M., Justice in the Church, A Fundamental Theory of Canon Law, English translation by Jean Gray in collaboration with Michael Dunnigan, Collection Gratianus Series, Wilson & Lafleur, Ltee, Montreal Canada 2009, 332 pages. ISBN 978-2-890127-918-5 in Philippiniana Sacra, vol. XLVI, no. 136 (January-April 2011), pp. 277-278.

Patricia M. Dugan (ed.), Towards Future Developments in Penal Law: U.S. Theory and Practice, a symposium held under the auspices of the Pontifical Council for Legislative Texts at the Pontifical University of the Holy Cross, Rome, March 5-6, 2009, Collection Gratianus Series, Wilson & Lafleur, Ltée, Montreal Canada 2010, 245 pages, ISBN 978-2-89127-935-2 in Philippiniana Sacra, vol. XLVI, no. 137, May-August 2011, pp. 511-512.

  1. H. Helmholz, The Spirit of Classical Canon Law, The Spirit of the Laws Series, Paperback Edition, University of Georgia Press, Athens, Georgia 2010, 514 pages. ISBN – 13:978-0-8203-3463-9 in Philippiniana Sacra, vol. XLVI, no. 138 (September-December 2011), pp. 827-828.

Hamilton Hess, The Early Development of Canon Law and the Council of Serdica, Oxford University Press, New York 2002, 279 pages. ISBN 0-19-826975-7 in Philippiniana Sacra, vol. XLVII, no. 139 (January-April 2012), pp. 253-254.

Piero Amenta, Administrative Procedures in Canonical Marriage Cases: History, Legislation and Praxis, translated from Italian by Marcus Francis and Christopher Hancock, English Edition revised by Joseph Blain, Collection Gratianus Series, Bibliothèque et Archives nationales du Quėbec Library and Archives Canada, Wilson & Lafleur Ltée 2011, 258 pages. ISBN 978-2-89127-981-9 in Philippiniana Sacra, vol. XLVII, no. 141 (May-August 2012), pp. 841-843.

William H. Woestman OMI, Papal Allocutions to the Roman Rota 1939-2011, Library and Archives Canada Cataloguing in Publication, Faculty of Canon Law, Saint Paul University, Ottawa 2011, Copyright 2011 by Libreria Editrice Vaticana on March 31, 2010,  326 pages, ISBN 978-0-9810616-1-0 in Philippiniana Sacra, vol. XLVII, no. 142 (September-December 2012), pp. 1119-1121.

Scientific, Ecclesial and Cultural Activities

  • Vice Rector, University of Santo Tomas, Manila (2020-present)
  • Associate Professor, UST Faculty of Canon Law, Manila, Philippines
  • Treasurer, Canon Law Society of the Philippines
  • Business Manager, Philippine Canonical Forum (Journal published annually by the Canon Law Society of the Philippines)
  • Conventual Councilor, Priory of St. Thomas Aquinas, University of Santo Tomas, Manila, Philippines (2003-2008).
  • Member, UST Board of Trustees (2014 – present)
  • Member, UST Academic Senate (2014-present)
  • Member, UST Corporación (2018 – present)
  • Dean, Ecclesiastical Faculty of Canon Law (First Term, 2017-2019)
  • Presiding Official, UST Canon Law Council (2017-present)
  • Regent, UST-AMV College of Accountancy (2007-present)
  • Chairman, Provincial Committee for the Regularization of the Brethren, Dominican Province of the Philippines (2015 – present)

Lectures/Seminars/Conferences Delivered:


  • Fr. Isaias Tiongco, OP JCD, “UST Faculty of Canon Law’s Response to the Holy See’s Instruction for the Reforms in the Study of Canon Law” in Proceedings of the Symposium on P. Francis’ Apostolic Constitution Veritatis Gaudium  on Ecclesiastical Universities and Faculties, sponsored by the Pastoral Institute and The Canon Law Institute of the Catholic University of Korea, Kim Sou-hwan Hall, South Korea, November 9, 2019.



  • Fr. Isaias Tiongco, OP JCD, Msgr. Edgardo Pangan JCD and Msgr. Mario Martinez JCD, “A Symposium on the Declaration of Marriage Nullity” given to a group of civil lawyers, 14th CLSP Convention, Monte Vista Resort, Diocese of San Pablo, Calamba City, Laguna, April 25, 2006.
  • Fr. Isaias Tiongco OP JCD and Msgr. Edgardo Pangan JCD, “A Primer on the Declaration of Marriage Nullity” given to lay faithful working in Matrimonial Tribunals, 15th CLSP Convention, Montebello Villa Hotel, Archdiocese of Cebu, Banilad Cebu, April 18, 2007. 

Lectures/Seminars/Conferences Attended:


  • UST Canon Law Week, Faculty of Canon Law, UST, January 7-8, 2010. 
  • UST Canon Law Week, Faculty of Canon Law, UST, January 7-9, 2009.
  • UST Canon Law Week, Faculty of Canon Law, UST, January 10-12, 2008.
  • UST Canon Law Week 2011, January 6-7, 2011 (Ad Misericordia ad Justitiam)
  • Penal Process and Canonical Remedy (Msgr. Edgardo Pangan, JCD)
  • Erring Priests and Aftermath (Most Rev. Mylo Hubert Vergara, D.D.) 
  • UST Canon Law Week 2012 (Canon Law: Its Relevance in the Face of the Modern Day Controversies)
  • Leaving the Priesthood: Canonical Procedures for the Dispensation from Priestly Ministry and Celibacy (Msgr. Rey Manuel Monsanto, JCD)
  • Normae de Gravioribus and other More Serious Crimes (Fr. Jaime Achacoso, JCD)
  • Civil Law Procedures (Criminal Law Procedures) (Atty. Ma. Liza Lopez-Rosario, DCL)
  • UST Canon Law Week 2013 (Of Doors and Keys: Faith and the Law)
  • Defection of Faith and Canonical Marriage (Fr. Danilo Flores, JUD)
  • Understanding Academic Freedom in the Catholic Church (Rev. Fr. Greg Bañaga, Jr., C.M.)
  • Intima Ecclesiae Natura – Integrating the Church’s Mission of Charity in the Philippine Context (Rev. Fr. Reginaldo Mananzan, S.J., JCD)
  • UST Canon Law Week 2014 (Canon Law and Canon Lawyers at the Service of New
  • Evangelization) January 7-8, 2014 Keynote speech: Most Rev. Teodoro Bacani, DD; January 7, 2014)
  • UST FACULTY OF CANON LAW LECTURE: Conference on Mitis Iudex Dominus Iesus (November 24, 2015) by Msgr. Edgardo Pangan, JCD & Rev. Fr. Danilo Flores, JUD
  • CICLSAL Praxis & Procedures of the Holy See with Regard to Institutes of Consecrated Life & Societies of Apostolic Life, UST Faculty of Canon Law, August 14-18, 2017, by Rev. Fr. Elias L. Ayuban, Jr., cmf, JCD
  • Administrative and Academic Officials’ Seminar and Teambuilding Activities; “Powering Up with People, Purpose, Passion”; June 16-19, 2014 St. Paul Renewal Center, Alfonso, Cavite
  • UST Canon Law Week 2017, UST February 9-10, 2017
  • “Emerging Challenges to Family Life in the Perspective of Canon Law” by Prof. Miroslav Konstanc Adam OP JCD (Roman Rota, Universitas Pontificium Angelicum)


  • 3rd CLSP Annual Convention, Marriage Nullity Declaration on Psychical Grounds:  Its Implications to the Family Apostolate/The Fundamental Rights of the Laity, L’Fisher Hotel, Bacolod City, 25-27 April 1995.
  • 4th CLSP Annual Convention, Empowerment of the Laity, Freemasonry, The Family Code of the Philippines, Maria Assumpta Seminary Cabanatuan City, 15-18 April 1996.
  • 5th CLSP Annual Convention, Canon 1095 Psychic Incapacities in Marriage Nullity Declaration Cases, Cagayan Capitol College Function Hall, Cagayan de Oro City, 7-10 April 1997.
  • 6th CLSP Annual Convention, Canonico-Pastoral Implications of Lay Organizations and Covenanted Communities/Temporal Goods of the Church, Asiaworld Resort Hotel, Puerto Princesa City, Palawan, 27 Apr-1 May 1998.
  • 7th CLSP Annual Convention, Current Issues/Tribunal Matters:  Prevailing Grounds in Matrimonial Cases/Parish Pastoral Councils, Sarabia Manor Hotel, Iloilo City, 12-16 April 1999.
  • 10th CLSP Annual Convention, CLSP:  A Decade of Service for Pastoral Renewal, Aklan Training Center, Kalibo, Aklan, 8-11 April 2002.
  • 11th CLSP Annual Convention, Business Inn, Canon Law at the Service of the Family, Bacolod City, April 28-May 1, 2003.
  • 12th CLSP Annual Convention, The Church and the Political Community:  Theologico-Pastoral Aspects of Political Life, Meralco Foundation, Talisay, Batangas, 19-24 April 2004.  
  • 13th CLSP Annual Convention, The Priest, Pastor and Moulder of Saints, MacArthur Park Beach Hotel,  Palo, Leyte, 16-19 April 2007.
  • 14th CLSP Annual Convention, “Current Issues of the Consecrated Life”, Montevista Resort, Pansol, Calamba City, 24-27 April 2006.
  • 15th CLSP Annual Convention,  Toward an Authentic Juridical Anthropology of Marriage/Jurisprudence in Marriage Nullity Under the New Code of Canon Law, Monte Villa Hotel, Banilad Cebu City, 16-19 April 2007.
  • 16th CLSP National Convention, The Penal Law and the Penal Process of the Church:  Crime and Punishment, Mallberry Suites Hotel, Cagayan de Oro City, 14-17 April 2008.
  • 17th CLSP National Convention, The Filipino Migrant Workers and their Families:  A Canonico-Pastoral Challenge to the Philippine Church, CAP Convention Hall, CAP Building, Vigan City, 21-22 April 2009. 
  • 18th CLSP Annual National Convention, Elijah Spirituality Center, Immaculate Heart of Mary Seminary, Tagbilaran, Bohol, 12-15 April 2010
  • Personal Ecclesiastical Circumscriptions by Fr. Eduardo Baura, JCD, Dean, Faculty of Canon law, Pontificia Universita della Santa Croce, Roma
  • The Priests in the Personal Circumscriptions:  Juridical Aspects
  • Towards a Personal Circumscription for Filipino Overseas Workers
  • 19th CLSP Annual National Convention, Towards a Canonical Status for Basic Ecclesial Communities, Hotel Tavern Surigao, Surigao City, 26-29 April 2011
  • Lights and Shadows: A Situationer on the BECS by Abp Orlando Quevedo, DD
  • Canonical Limits of the BEC:  A Review of the Instruction Ecclesia de Mysterio (1997) and Other Documents by Fr. Jaime Achacoso, JCD 


  • BECs and the Prophetic Mission of the Church
  • BECs and the Priestly Mission of the Church
  • BECs and the Kingly Mission of the Church
  • 20th CLSP Annual National Convention, From “Sacramentorum Sanctitatis Tutela” to “Delicta graviora”: A Case for Liturgical Fidelity, Hotel Centro, Puerto Princesa City, Palawan, 16-19 April 2012
  • Lex Orandi, lex credenda:  Mutual Relationship between Liturgical Practice and Doctrine of the Faith by Prof E. Bermejo
  • The Process for the Dismissal from the Clerical State by Arch Oscar Cruz, JCD
  • Proposed Guidelines for Handling Cases of Sexual Misbehavior of Clerics by Msgr. Bernard Pantin, JCD
  • 21th CLSP National Convention 2013, Bacolod, April 8 – 11, 2013. 
  • “From the Barangay to the World: Towards a Guidelines for BECs and a Personal Prelature for OFWs”
  • 22nd CLSP National Convention 2014, Malvar, Batangas
  • “The Filipino Laity and the New Evangelization”
  • The Canonical Status of the Layperson (Prof. Luis Navarro, Dean of the Faculty of Canon Law, Pontifical University of the Holy Cross in Rome)
  • The Pastoral Demands of the New Evangelization (Fr. Jaime B. Achacoso,JCD)
  • New Ecclesial Movements in the Papal Teachings and its Juridical Implications (Prof. Luis Navarro)
  • The Dispensation from the Clerical State: Procedure (Prof. Luis Navarro)
  • 23rd CLSP National Convention 2015, Dumaguete City, Negros Oriental
  • “Academic Freedom and Catholic Education: A Symposium on the State of Catholic Education in the Philippines” by Prof. Stefan Muckl, JCD Pontificia Universita della Santa Croce, Roma
  • 24th CLSP National Convention 2015, Cagayan de Oro City, Misamis Oriental, “Challenges to Marriage and the Family” by Prof. Nilo Divina,JD (Dean, University of Santo Tomas Faculty of Law) & Archbishop Oscar Cruz,DD JCD (Judicial Vicar, National Appelate Matrimonial Tribunal)
  • 25th CLSP Annual Convention, Mercy and Compassion in the Matrimonial Process (From Amoris Laetitia to Mitis Judex and Beyond: The Canonical Provisions for the Pastoral Care of Problematic Matrimonial Situations” by Prof. Miroslav Konstanc Adam,OP,JCD, Roman Rota, Universitas Pontificium Angelicum)), Oriental Hotel, Legazpi City, Albay 13-16 February 2017.
  • 26th CLSP National Convention, “The Clergy and Consecrated Persons towards the New Evangelization”, Main speaker: Fr. Elias L. Ayuban Jr., CMF JCD, Marco Polo Hotel, Davao City, February 26 to March 1, 2018.
  • 27th CLSP National Convention, “Collaboration between the Philippine Church and the State”, Quest Hotel and Conference Center, Cebu City Feb. 18-21, 2019.


  • International Convocation of Heads of Faculties/Institutions of Canon Law sponsored by the Congregation for Catholic Education, Pontificia Università della Santa Croce, Piazza di Sant’ Apollinare 49 Roma, October 20-21, 2016
  • Continental Meeting of Rectors, Deans and Directors of Ecclesiastical Universities and Faculties on the Apostolic Constitution Veritatis Gaudium, Assumption University, Suvarnabhumi Campus, Bangkok, Thailand May 11, 2018

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