Lying is probably one of the most common wrong acts that we carry out. Most people would say that lying is always wrong, except when there is a good reason for it, which means that it is not always wrong.
Different theories of ethics approach lying in different ways.
Consequentialists are concerned with the consequences of lying and if telling a lie would lead to a better result than telling the truth. Deontologists base their moral thinking on general universal laws.
An act is therefore either a right or a wrong act, regardless of whether it produces good or bad consequences.
Some philosophers believe that lying requires a statement of some sort; they say that the liar must actually speak or write or gesture. Some philosophers believed that lying was always wrong.
Lying to someone is not treating them as an end in themselves, but merely as a means for the liar to get what they want. If there was a universal law that it was generally ok to tell lies then life would rapidly become very difficult.
Everyone would feel free to lie or tell the truth as they chose, it would be impossible to take any statement seriously without corroboration, and Society would collapse.
The reason for lying that gets most sympathy from people is lying because something terrible will happen if you do not lie. Examples include lying to protect a murderer’s intended victim and lying to save oneself from death or serious injury.
These lies are thought less bad than other lies because they prevent a greater harm occurring; they are basically like other actions of justified self-defence or defence of an innocent victim.
Since such lies are often told in emergencies, another justification is that the person telling the lie often has not time to think of any alternative course of action.
Threatening situations do not just occur as emergencies; there can be long-term threat situations where lying will give a person a greater chance of survival. In a famine lying about whether you have any food hidden away may be vital for the survival of your family.
When two countries are at war, the obligation to tell the truth is thought to be heavily reduced and deliberate deception is generally accepted as part of the way each side will try to send its opponent in the wrong direction, or fool the enemy into not taking particular actions.
In the same way each side accepts that there will be spies and that spies will lie under interrogation (this acceptance of spying does not benefit the individual spies much, as they are usually shot at the end of the day).