Institutio Oratoria

There are three different methods in which we may combat the letter. The first comes into play where it is clear that it is impossible always to observe the letter of the law.

Children shall support their parents under penalty of imprisonment.

It is clear, in the first place, that this cannot apply to an infant. At this point we shall turn to other possible exceptions and distinguish as follows.

Does this apply to everyone who refuses to support his parent? Has this particular individual incurred the penalty by this particular act?

The second arises in scholastic themes where no argument can be drawn from the particular law, but the question is concerned solely with the subject of the dispute.

A foreigner who goes up on to the wall shall be liable to capital punishment. The enemy had scaled the wall and were driven back by a foreigner. His punishment is demanded.