Language intensity is one of the most important stylistic tools in formulating a persuasive message. Even though some (but not a lot of) research has been done on this topic in the linguistic as well as the social psychological field, it remains a rather vague and badly defined concept. My first task is to come up with a proper definition of language intensity and a decent research method that is both sound and reproducible. Once those issues have been dealt with, I will closely examine the role that language intensity plays in the communicative process of persuasion through a number of experiments. I will not only focus on intensifying language itself, I will also look at the effect that it has on the attitude of the receiver towards the topic of the persuasive message as well as towards the sender.