The principal should spank her for failing principles of the English language.

Anywhere except New Albany, you’d be forgiven for thinking that a “college professor” should know the difference in usage between an adjective and a noun. Sadly, the crusading Vickster’s imaginary academic alter ego does not.

ACCOUNTING PRINCIPALS... INDIANA STATE BOARD OF ACCOUNTS

Perhaps 3rd district councilman Steve Price can compose a resolution providing “feel good” funding for Erika’s continuing linguistic education, but until that unlikely day, consider …

Principal is both an adjective, which means that it modifies a noun, and a noun. In the adjectival sense, it means, “First, highest, or foremost in importance, rank, worth, or degree; chief.” As a noun, it has several meanings, none of which are applicable to Erika's mistaken usage.

Principle is a noun – it names something – and in the sense that Erika should have used it, it means, “a fundamental, primary, or general law or truth from which others are derived: the principles of modern physics.”

Or, one might say: "The principal principles of the trognonymous Freedom of Speech blog are cowardly subterfuge and malice."

Glance here for accounting principles correctly used.

See, there really are rules, Erika. You simply must learn them.

Thanks to http://dictionary.reference.com/ for definitions.