Rav Kook deals with the unproductive problem of daydreaming, sexual fantasy and pornography, and how it lowers one into a feeling of depression and loneliness, precisely missing the companionship that a true soul-mate is meant to be. He also deals with the problem of cursing, swearing and unclean speech, and the relationship between our thoughts, speech and actions, whether when used properly or misused. The power of speech is also directly connected with the Land of Israel where Hebrew, prophecy and leprosy for Lashon HaRa are apparent. This helps us understand speech in a modern context.
The trait of modesty, so imbedded in the Nation of Israel, has served as the foundation for all the giant spiritual advances achieved by the Jews throughout history. This is why the Torah laid so strong an emphasis on maintaining modesty and sanctity.