The Law of Conservation of Apostrophes is a humorous concept introduced in Lynne Truss's book "Eats, Shoots & Leaves." This idea suggests that over time, the omission of apostrophes in words like "it's" leads to a balancing effect, where an additional apostrophe appears in words like "its." Essentially, this law implies that the total number of apostrophes used in language remains constant, regardless of how they are used.

This whimsical notion has been referred to as a heresy since the 13th century, highlighting the importance of proper punctuation in maintaining clarity and meaning. Truss uses this concept to emphasize the significance of apostrophes and encourages readers to pay close attention to their usage in writing.