Backing

• Backing bolsters the warrant, not the claim itself. While grounds supply evidence directly for the claim, backing supplies evidence that makes the warrant credible. In other words, grounds support what you want an audience to accept, but backing explains why your (again, usually unstated) warrant holds up.

• In the example above about water contamination, the backing for the warrant "pressure below 20 psi often draws harmful contaminants into the water system" might be scientific studies, water testing reports, and other reasons why "pressure below 20 psi often draws harmful contaminants into the water system" is reasonable.