Charles Bradlaugh & Anthony Collins 
Half-Hours with the Freethinkers [PDF ebook] 

Have you ever played the parlor game where you name the historical figures you’d like to invite to a dinner party? This fascinating book is kind of like the written form of that exercise. It brings together the key arguments and beliefs espoused by an array of the top minds in the 'free thought’ movement, a philosophical school that prized rationality and logic over dogma. It’s a must-read for those interested in learning more about philosophy in user-friendly, bite-sized essays.