The Latin term “arguendo” translates literally as “for the sake of argument.” In a legal context, it refers to a statement being made for illustrative purposes or to explore a legal situation, without specifically admitting anything or making any firm claims. This term often comes up in briefs filed with appeals, although it may also be used in the courtroom. Judges can also ask attorneys involved in a case to “assume arguendo,” responding to assertions as though they were true for the purpose of exploring the ramifications of a situation.
One of the most common applications of this concept in law comes up when an attorney responding to a claim made by the other side decides to assume for the sake of argument that the claim is true. The attorney indicates that an argument is being made arguendo, not admitting that the claim is true, but theorizing as though it is. The attorney can respond to the claim with a line of thinking explaining how the specifics of the situation prevent the case from being pursued, if the claim as made is true.
For example, an attorney could say “assuming arguendo that my client killed Mr. Jones, the death occurred in the course of a burglary while Mr. Jones was armed, and my client was clearly acting in self defense.” In this case, the attorney suggests that even if the claim is true, the charges against the client cannot be pursued as laid out.
Preceding a statement with a note that it is being made arguendo acts as a flag to alert everyone present to the fact that the attorney is not admitting anything with the statement, and that the statement does not have a bearing on the rest of the case. This allows attorneys to explore hypothetical situations and explanations in court while presenting their cases, without endangering their clients or confusing the court. Flagging written statements with this word works in much the same way and allows attorneys to articulate thoughts and ideas while preparing appeals and other documents for a judge to review.
The concept of making assumptions for the sake of argument or discussion has spilled over into the general population as well. It is common to see people making a statement arguendo in debate or discussion, usually preceding it with “let's assume for the sake of argument that...” to make sure the other parties in the discussion understand that a point is not being ceded, but rather explored further for the purpose of having a more in-depth discussion.