The bad part of the enlightenment

It is undoubtable that the Enlightenment of western civilization during the 1700's was a great time for humanity. We gained ground as a species in many ways including philosophy. The main theme of the time was becoming free to discuss and think and to break away from what the church had been forced down peoples throats. I find it odd that in a time where people were being "enlightened," they were also developing the idea of racism , one of the most vacuous concept ever to exist. When ever I thought of the enlightenment I always thought of a time of growth. Now however, I will constantly be reminded of the fact that racism was developed during this seemingly darker part of our history.