Many disagree with Chazal and claim that when the Torah refers to the principle of "an eye for an eye," the Torah means it literally.
We find reference to the concept of "an eye for an eye" in this week's parsha, Mishpatim, and I think that a careful analysis shows that it is not meant literally but is metaphor.
Consider that nowadays people often refer to the principle of "an eye for an eye" and do not mean it literally - that is, they are not in favor of actually knocking out someone's eye, or raping a rapist, etc. Rather, they are in favor of harsh punishment commensurate with the severity of the crime. In specific instances, this means capital punishment for a murderer, but it is not meant to be literally an eye for an eye. It is a metaphor, and the invocation of a legal principle.
True, if we look at the code of Hammurabi and other texts which preceded Matan Torah, we see that they took the principle of an eye for an eye literally. Thus, we see that a builder who built a shoddy building which collapsed and killed the owner's son has his own son killed. However, "an eye of an eye" would not apply to such an extent in Torah law , for we have the principle that a son is not put to death for the sins of his father. Also, that the principle preexists the giving of the Torah means that when the Torah invokes it, it is referring to a well-known legal precedent, and does not then need to mean it literally, but rather can use it as metaphor, just as we do today.
I believe a close reading of the principle as it is found in parshat Mishpatim bears out the idea that it is metaphor and not meant to be taken literally. The citation is Shemot 21:22-27:
"If men strive, and hurt a woman with child, so that her fruit depart from her, and yet no mischief follow: he shall be surely punished, according as the woman's husband will lay upon him; and he shall pay as the judges determine.
And if any mischief follow, then thou shalt give life for life,
Eye for eye, tooth for tooth, hand for hand, foot for foot,
Burning for burning, wound for wound, stripe for stripe.
And if a man smite the eye of his servant, or the eye of his maid, that it perish; he shall let him go free for his eye's sake.
And if he smite out his manservant's tooth, or his maidservant's tooth; he shall let him go free for his tooth's sake."
We begin with two cases, in which a man strikes a woman and causes her to miscarry. In the first instance "mischief" follows; in the other it does not. What is the nature of this "mischief" - in Hebrew, "Ason?"
In another context, Chazal say that "Ason" only means death. The context is Yaakov's reluctance to send Binyamin with his brothers to Egypt lest "Ason" happen to him. In the context of Yosef's apparent death, it is likely that this is the fate Yaakov fears for Binyamin.
In our context as well, death is a fitting explanation for "Ason." Consider that this mischief is accompanying a miscarriage. In the old days, childbrith and miscarriages were often fatal, and so death might accompany a miscarriage. On the other hand, a miscarriage could not cause a woman to lose an eye or a tooth, or to be burnt.
Thus, in the first case, when she does not die as a result, all the assaulter does is pay a fine imposed by the court. If she dies as a result of the miscarriage, and thus as a result of the injuries he inflicted upon her, then he receives the death penalty - as the verse states, "And if any mischief follow, then thou shalt give life for life."
As I stated above, the remainder does not make sense in context. What eye for what eye? What tooth? What burn? She does not get these injuries associated with a miscarriage!
Rather, what we see here is an appeal to a legal principle, invoking it as a metaphor. Since he caused her to die, the only fitting punishment is to take a life in enchange for her life. The remainder is just a list which accompanies it - it is part of the litany - but is not meant in any way to be binding law.
Indeed, if we were imposing the principle of an eye for an eye consistently in this case, he should not be able to get away with paying a fine. If the assaulter had a pregnant wife, they should induce a miscarriage in punishment. (And they should kill the assaulter's wife rather than him - which I indeed have no proof according to those who say an eye for an eye is literal that they did not do, but which seems foriegn to the ear.)
It is also possible and perhaps likely that "an eye for an eye" is actually applicable in both cases, as the cases form a set. In this reading, "an eye for an eye" is a legal metaphor which means that we deal with the crime in accordance with its severity. If he killed an actual person, then he pays a life - his own - for her's. If he only killed a fetus, then this is less severe, and his punishment finds the level of severity appropriate to it, which is in this case paying a fine. Thus, following "a life for a life," we have "an eye for an eye, a tooth for a tooth, etc," in that we realize there are degrees of injury and we downgrade the punishment to match the injury, and in impose only a fine and not capital punishment. (Thus, an eye for an eye and not a life for an eye.)
This actually accords with Chazal's understanding, which is that "an eye eye for an eye" means monetary payment for an eye, while "a life for a life" means capital punishment.
The next case is that of the servant, with an actual eye or tooth knocked out. This might be brought by way of aside, the Torah having been reminded of this case by the wording of the metaphor/legal principle it just invoked.
Alternatively, we are seeing here a legal reform on behalf of slaves. In general damaging an eye would require monetary redress. However, in order to discourage maltreatment of servants, the Torah *increases* the punishment such that instead of paying a fine, the owner must free his servant entirely. Thus, the value of a servant for an eye, rather than the value of an eye for an eye.
In sum, there seems to be a tendency to assume the pshat reading here is a literal one, which is strange, considering that often drash is hyperliteral and significance maximalist, and pshat is hypoliteral and significance minimalist. The best pshat in this instance may well be in this instance that we are seeing a metaphor and appeal to a legal principle without subscribing to that principle in all its details.