Online Guide to Ethics and Moral Philosophy


Robert Cavalier

Philosophy Department
Carnegie Mellon

Part I History of Ethics

Preface: The Life of Socrates
Section 1: Greek Moral Philosophy
Section 2: Hellenistic and Roman Ethics
Section 3: Early Christian Ethics
Section 4: Modern Moral Philosophy
Section 5: 20th Century Analytic Moral Philosophy

Part II Concepts and Problems

Preface: Meta-ethics, Normative Ethics and Applied Ethics
Section 1: Ethical Relativism
Section 2: Ethical Egoism
Section 3: Utilitarian Theories
Section 4: Deontological Theories
Section 5: Virtue Ethics
Section 6: Liberal Rights and Communitarian Theories
Section 7: Ethics of Care
Section 8: Case-based Moral Reasoning
Section 9: Moral Pluralism

Part III Applied Ethics

Preface: The Field of Applied Ethics
Section 1: The Topic of Euthanasia
Multimedia Module: A Right to Die? The Dax Cowart Case
Section 2: The Topic of Abortion
Multimedia Module: The Issue of Abortion in America
Postscript: Conflict Resolution

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In an article entitled "On a Supposed Right to Lie from Altruistic Motives," Kant interprets a case of 'the Murderer at the Inn.' Imagine that you are an Inn keeper and a terrified man runs past you and up the stairs. Shortly thereafter, a brute appears and -- clearly angry and looking for blood -- asks you if that man is in your dwelling. What should you do, tell the truth (and reveal that the man is upstairs) or tell a lie (and perhaps save that man's life)? Kant responded as follows:

"For instance, if by telling a lie you have prevented murder, you have made yourself legally responsible for all the consequences; but if you have held rigorously to the truth, public justice can lay no hand on you, whatever the unforeseen consequences may be. After you have honestly answered the murderer's question as to whether this intended victim is at home, it may be that he has slipped out so that he does not come in the way of the murderer, and thus that the murder may not be committed. But if you had lied and said he was not at home when he had really gone out without your knowing it, and if the murderer had then met him as he went away and murdered him, you might be justly accused as the cause of his death. For if you had told the truth as far as you knew it, perhaps the murderer might have been apprehended by the neighbors while he searched the house and thus the deed might have been prevented. Therefore, whoever tells a lie, however well intentioned he might be, must answer for the consequences, however unforeseeable they were, and pay the penalty for them even in a civil tribunal. This is because truthfulness is a duty which must be regarded as the ground of all duties based on contract, and the laws of these duties would be rendered uncertain and useless if even the least exception to them were admitted. To be truthful (honest) in all declarations, therefore, is a sacred and absolutely commanding decree of reason, limited by no expediency."
In taking this 'absolutist' stand, Kant was following in a tradition represented by, for example, St. Augustine in his work The Enchiridion

"But every liar says the opposite of what he thinks in his heart, with purpose to deceive. Now it is evident that speech was given to man, not that men might therewith deceive one another, but that one man might make known his thoughts to another. To use speech, then, for the purpose of deception, and not for its appointed end, is a sin. Nor are we to suppose that there is any lie that is not a sin, because it is sometimes possible, by telling a lie, to do service to another."


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Copyright 2002 (first published 1/96)

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