Nietzsche, of course, had some better ideas later -- also some worse ones.
There are many difference between lies and mistakes.
Lies are deliberate; mistakes are usually accidental. Unless Freud's idea are correct, all mistakes are innocent, which is why Nietzsche classified them as non-moral, not immoral.
Your mistakes can cause others to misunderstand a situation -- which doesn't mean you actually want that to happen.
Lying is blameworthy because it is a form of deliberate deception, and deception is blameworthy for reasons that appear below. In the meantime, it should be remembered that silence and innuendo can also deceive.
Lying can be defined as: Making statements that are untrue and intended to deceive. Lies have to be written or spoken or implied by something that is written or spoken. Mistakes, on the other hand, can be verbal or non-verbal.
There are hundreds of different ways to make a mistake but only a few ways to tell lies.
Is it always wrong to tell lies? The philosopher Immanuel Kant thought so. He gave a strange reason, as follows:
Suppose you have a friend staying in your house. Some bad men come to your door seeking to harm your friend. Suppose you lie to the bad men, saying: "My friend has fled to the woods." Suppose that, unbeknown to you, your friend has indeed fled to the woods and is therefore caught by his enemies. Kant said you would then feel very bad, whereas if you had told the truth you would feel OK. He concluded that lying is never permitted.
There are surely better reasons to favor truthfulness than this one. One reason has to do with the human tendency to form habits.
In general it is bad to deceive people, although there might be exceptions. But if you allow yourself an occasional lie in an extreme case you will form a habit of lying and end up telling lies for ignoble reasons.
This invites the question: Is it all right to deceive bad people by means other than lies, that is, by non-verbal means? By silence, say, or winking, or shrugging one's shoulders? To this question some philosophers have answered "Yes" partly because they hold that lying subverts the proper use of language, which is to convey truths. But silence, winks and shrugs have no general purpose or proper use and therefore cannot be misused.
On the other hand deception by roundabout means can also become a habit.
Is it ever right to deceive others for benevolent reasons?
For much of the 20th century, and probably also before that, the ethos of the medical professions in England and Australia, and probably in some other Western countries as well, was that terminally ill children and adults -- but not their parents and relatives -- should be lied to.
Were physicians actually taught to tell lies? Medical students are educated by doctors and doctors usually transmit what they take to be the Hippocratic ethic -- in this case, the supposed need to lie to the dying.
Some physicians rejected that interpretation of the ethic and gave straight answers to teenagers and adults who asked straight questions -- pointing out, however, that there is no need to tell direct lies to very young children and that older children and adults do not always ask the doctor "Am I dying?"
Thirty or 40 years ago, the ethos was abandoned as causing more pain than truthfulness.
Sisela Bok in her excellent book "Lying" showed that whenever you lie, even from benevolent motives, you rob people of their freedom. If a doctor tells a dying man that he will recover, the patient loses a reason, and thereby the freedom, to seek a second medical opinion or try a new experimental cure.
He won't voice his wishes regarding his funeral and might not make a will. A Christian wanting the last rites might not get the opportunity to arrange that.
Most lying, however, is not benevolent. Lies are told to benefit the liar or to harm others. The businessman tells lies about his shoddy wares or, in some cases, to dodge prosecution. Politicians tell lies in order to bluff voters into voting for their parties.
These liars are opposed to freedom -- for other people.
(Jenny Teichman was the John Findlay Visiting Professor of Philosophy at Boston University in the spring semester of 2002. She is an emeritus fellow of New Hall College in the University of Cambridge and author of several books including one about illegitimacy.)