We head uphill, across crumbly volcanic rock through a narrowing defile that rises to the top of a ridge.

BBC: Iceland on horseback

Let us not forget that hatred, envy and pride defile our lives!

CNN: Text of Pope Francis' homily

It calls for the murder of homosexuals, the mistreatment of women, the flogging and stoning of those accused of adultery, the killing of apostates and girls who defile their family's "honor" by dating non-Muslims or wearing pants or make-up, etc.

CENTERFORSECURITYPOLICY: Kagan's Shariah problem

Since I'm frankly at a loss to comprehend why anybody would defile the countryside I, perhaps unfairly, put the perpetrators in the same antisocial category as arsonists and murderers I decided to call Wesley Schultz, a professor of psychology at California State University at San Marcos, for added perspective.

WSJ: Recycled Emotions