From the birth of Christianity to the present day, conscience has been a prominent and essentially contentious concept in Catholic moral theology and tradition. Catholic theologians have, for centuries, engaged in generating elaborate treatises on the meaning, nature, primacy, role and formation of this human capacity for moral choice. The concept has raised bitter, divisive and damaging disputations in history between individual conscience and perceived objective truth that is subjective/objective dilemma. For instance, Martin Luther unapologetically asserted that: I am bound by the Scriptures I have quoted and my conscience is captive to the Word of God. I cannot and will not retract anything, since it is neither safe nor right to go against conscience. 1. In the presence of ecclesiastical and political leaders, Luther has done no less than to proclaim his ‘captive’ allegiance to the doctrine of the primacy of conscience. In response to such a declaration, the Secretary to the Diet of Worms remonstrated with Luther as follows: Lay aside your conscience, Martin; you must lay it aside because it is in error; and it will be safe and proper for you to recant. Although you say the councils have erred you will never be able to prove it, in matters of faith at least, and even in matters of moral I fancy it will be with much difficulty. 2. Amongst the issues raised by this response, issues that are dealt with during the course of this thesis, are that: (i) the primacy of conscience will inevitably lead to conflict between the individual and the institutions, be they political or ecclesiastical; (ii) the expectation that the individual conscience should ‘naturally’ defer to the professionalised ‘wisdom’ of the institution; (iii) the ecclesiastical management of the erroneous conscience; and (iv) even in the event of the institution being in error, it is better that the individual recant his or her own insights and continue to obey institutional edicts because as a minority of one, he or she will always find it inherently difficult to satisfactorily establish such institutional error. There are some, however, who would argue at this stage that far from exercising the primacy of conscience Luther is actually concretising what John Henry Newman was to later describe as “the right of self-will.” 3. Luther’s solitary, but principled stand foreshadows Mahatma Gandhi’s assertion that, “In matters of conscience, the law of the majority has no place.” 4. While matters of conscience for today’s Catholics usually enter their consciousness at less grandiose levels than those experienced by Martin Luther, such Catholics are nonetheless faced with morally demanding struggles. Hence, this thesis examines the Church’s interaction with conscience as she seeks to “inform” it as to how Christians should respond in moral areas. It also seeks to examine the individual Catholic’s personal conscientious management of such modern moral dilemmas from a stance that is informed by the ethical notion of intrinsece malum or malum in se, 5. for example. This thesis undertakes such a task through the ‘lens’ of the thinking, theories and life experiences of these theologians: John Henry Newman, Germain Grisez and Linda Hogan, all of whom are absolutely convinced of the notion that conscience is a unique but complex human phenomenon that cannot and must not be ignored or mismanaged. It is in the light of their unique contributions to the study of the notion of conscience, then, that this thesis seeks answers to the following questions: 1. What does conscience mean in a pluralist society that is characterised by individualism, subjectivism, relativism and very diverse moral values? 2. What roles, functions or goals do these scholars assign to conscience? 3. What is their understanding of the term “primacy of conscience”? 4. How do they relate conscience to the intention and circumstance of human actions? 5. What is their response, if any, to the prospect of the individual conscience against specific moral church teaching? 6. In the inevitable event of such conflicts occurring, what solutions do these scholars proffer in order that they be resolved? 7. How do these scholars relate conscience to the role of the Holy Spirit (teacher of truth)? 8. To what extent, if any, does their understanding of the notion of a Christian conscience differ from, or closely interrelate with, the notions of goodwill and truth? 9. How do they treat erroneous conscience in terms both of the ‘informing Church’ and the ‘misguided’ Catholic? AIM AND PURPOSE OF THE THESIS As already noted, this thesis draws from ongoing modern theological enquiry evidenced in the works of the English clerical scholar, John Henry Newman, the American lay moral theologian, Germain Grisez, and the Irish moral theologian, Linda Hogan. As with the overall history of the study of conscience, the writings of these scholars on the nature and function of conscience reveal distinctive differences in the moral theological views they represent. Newman’s general approach to the topic could be characterised as being distinctively religious, while Grisez’s is driven by philosophical/conformist principles and Hogan’s by the tenets of personalism. The thesis evaluates the usefulness and efficacy of these distinctive approaches by examining them in relation to the overall teaching tradition of the Catholic Church.