The Enlightenment Philosophers| Valentine's Day Activities for 9th, 10th, 11th, 12th Graders is the perfect blend of study/review material and a deeply engaged activity for students. Students start with the first part of the activity in an open note quiz on ten philosophers covered in class. My class utilizes our World History textbook (Strayer Version 4) but even a simple internet search can yield some of the basic characteristics of the chosen philosophers. Examples of Philosophers:RousseauVol