The Ten Commandments have played an important role in shaping Judaism, Christianity, and the Western World. Many an outcry have been made regarding the public display of the Ten Commandments. In recent memory, the Supreme Court has made two rulings on the matter: McCreary County v. ACLU (2005) and Van Orden v. Perry (2005). In the former, it was ruled unconstitutional because it promoted religion, whereas in the latter, it was considered constitutional because it was secular in its meaning. I would like to point out the irony that the Supreme Court ruled on both of these contradictory rulings on the same day: June 27, 2005! This example of case law epitomizes the confusion that America has on the role of religion in America.
If we set the Supreme Court's bewilderment aside for a moment, there is a way where we can clearly see if there is establishment of religion going on here. Let's take a look at the Jewish version (i.e., the original and correct version) of the Ten Commandments:
Does this version match up with the Christian version? The answer is "no," but needs elaboration. Not only is the answer "no," but the Protestants and Catholics cannot even agree upon what the Ten Commandments are. The Catholics combine the First and Second Commandments. They then make Commandment #9 not coveting your neighbor's wife, and Commandment #10 is not coveting your neighbor's goods. In Judaism, the Tenth Commandment is an all-inclusive commandment against coveting. In the Protestant version, they do away with the First Commandment all together. They split up the Jewish version of the Second Commandment, which reads as following: #1: Thou shall not have other gods before me. #2: Thou shall not make graven images.
Since America has historically been predominantly Protestant, the version that has been displayed is the Protestant version. Since preference has been given to one version over the other, the display of the Ten Commandments on public property violates the Establishment Clause, thereby making it unconstitutional.