Christians have wrestled with conscience from Christianity’s beginning to the present. Does it exist? Do religious and nonreligious people have it? Is conscience a subjective or objective reality? Christians have asked if it is God’s voice, human beings’ own voice, or the voice of the community. Is conscience found in natural law? Is it a combination of the mind, will, heart, and/or the soul? Is it a divine judgment or a self-evaluation? What are the consequences of following an erroneous conscience? Lately, questions have arisen about conscience in a pluralistic society. What ought to be the relationship between conscience and law? Commentators also struggle with questions about accommodating institutions’ conscience claims. Which institutions might qualify and why? Lawmakers also contend over conscience claims made by individuals concerning military service, or over state laws about family matters increasingly at odds with Christian commitments. This book explores sources having lasting influence upon questions about conscience, including the New Testament, Aquinas, Luther, Calvin, Roger Williams, US federal and state constitutions, and Pope Benedict XVI, among many others.

Nathan Chapman considers the link between free exercise and freedom of conscience in the US Constitution and legislation. Some theorists emphasize the similarity between religion and other moral or philosophical commitments and insist there is no reason to privilege the former over the latter. However, for the founding generation, freedom of conscience meant religious freedom, exercised as a response to one’s duty to God. Courts and legislatures often negotiate different relationships between freedom of religion and of conscience. Speech, press, and association rights have been employed to protect conscience. And some state and federal statutes accommodate religion and other commitments under the label of conscience. However, the Free Exercise, Establishment, and Equal Protection Clauses have not been interpreted to prioritize nonreligious conscience. The Supreme Court has interpreted the law about conscientious objection to military service to include non-theistic beliefs. Some statutes accommodating religion also protect nonreligious beliefs or practices, for example, statutes governing abortion, physician-aided suicide and capital punishment.

Kent Greenawalt discusses the permissibility, scope, and rationale for law to provide exemptions to protect religious and nonreligious conscience in the United States. It may be difficult for the law to determine which sentiments amount to conscience given differences in individuals’ perception and the strength of their convictions. Even the notion of a religious conscience is complex. Religious citizens’ conclusions about matters of interest to religion may proceed from both religion and reason, or only from reason. It is not clear what should count as religious, given differences between denominations and their ideas over time. There are a host of factors bearing on the permissibility and wisdom of granting exemptions, determining their scope, and deciding whether to extend protections to nonreligious conscience. A first principle is the importance of respect for others and for tolerance in a democracy. These questions about exemptions can be considered by looking closely at contested issues, like objection to the military draft, laws governing the manner of killing animals, ingestion of banned substances, abortion, and objection to insurance mandates concerning contraceptives.