This notorious experiment was designed as a response to the notorious trials of Nazi war criminals, who claimed that they were 'just following orders'. Milgram wanted to establish whether people really would obey authority figures, even when the instructions given were morally wrong.
The main thing to remember, when judging the experiment is that modern day criticisms have the benefit of hindsight. A few decades ago, Europe had been mentally scarred by the atrocities committed during the Second World War, and was looking for answers.
Even a few years later, in the 1960s, these wounds remained; as a Jew himself, Milgram was trying to establish whether the claim of war-criminals, that they were just obeying orders, was a reasonable defense or not.
At the time, the Milgram experiment ethics seemed reasonable, but by the stricter controls in modern psychology, this experiment would not be allowed today. Milgram's generation needed conclusive answers about the 'final solution', and some closure on this chapter of human history. Was human nature inherently evil or could reasonable people be coerced by authority into unnatural actions?
The Milgram experiment once again became relevant in the 1970s Mai Lai massacre, with society questioning the motives behind the, as well as other atrocities committed by the Americans in Vietnam. Whilst the actions of the soldiers concerned cannot be condoned, it showed the horrible effects on the psyche, and morals, of young men when they are exposed to death and suffering on a daily basis.
The main concerns raised about the Milgram Experiment ethics are based on a number of factors.
Modern ethical standards assert that participants in any experiment must not be deceived, and that they must be made aware of any consequences. In the interest of fairness, follow up research, performed after the experiment, indicated that there were no long term psychological effects on the participants.
However, the fact that these people thought that they had caused suffering to another human being, could have caused severe emotional distress.
Whilst the Milgram experiment appeared to have no long term effects on the participants, it is essential that psychological studies do have strict guidelines; the Stanford Prison Experiment is an example of one such study that crossed the line, and actually caused measurable psychological distress to the participants.
In some cases, this emotional scarring lasted for months and years after the study, so questioning the Milgram Experiment ethics is a necessary part of science.
The long term effect of carrying on performing similar studies would be destructive for research without deception. Much of psychology researches explore areas where the involved subjects are more skeptical than the average of the population.
They might never agree to participate in research which is harmless or aimed to help the subjects if it was well known that researchers commonly use deception.
In conclusion, whilst there is no doubt that the experiment, in its original format, would not be allowed, it is important to remember that Stanley Milgram was not a bad person. He was genuinely trying to uncover the reasons why humans could become embroiled in great evil.
In modern times, with questionable practices being carried out at Abu Ghraib and Guantanamo Bay, the Milgram and Stanford Prison experiments are once again becoming relevant.