Once a atheist went to Pope and said: "Pope, I am an atheist". Pope asked: " Have you read the Bible". Atheist says "No". Have you read the "Gita or Quran or any other book of a religion". Atheist says " No". Pope says " Then my friend , you are an ignoramus not an atheist".
I am an agnostic. Periyar was not an atheist he was an ignoramus.