Rudolf Otto (1869 - 1937) was a German Lutheran theologian, philosopher, and comparative religionist. He is regarded as one of the most influential scholars of religion in the early twentieth century.
I had requested his classic "The Idea of the Holy" 3 years ago but just added two more books of his to the suggestions board.
VOTE HERE:
Absolutely foundational for anyone who claims to study religion. I voted.
Is his verbiage understandable, or high-falutin convolutions that net much unexplained?
A first grader would generally find him incomprehensible; a high-school senior with an interest in religion or the social sciences would consider him readable. That is assuming that your standards for a high school education are similar to mine.
Thanks, MJ. I will up-vote these books.