Many pilgrims also put themselues vnder the chariot wheeles, to the end that their false god may go ouer them: and al they ouer whom the chariot runneth, are crushed in pieces, and diuided asunder in the midst, and slaine right out. Yea, and in doing this, they think themselues to die most holily and securely, in the seruice of their god. And by this meanes euery yere, there die vnder the said filthy idol, mo then 500.[Journal of Friar Odoric]
So why is monotheism good and polytheism bad? The simple answer comes from these words in the Ten Commandments: “Do not have any other gods before me” and “You shall not make for yourself an idol, whether in the form of anything that is in heaven above, or that is on the earth beneath, or that is in the water under the earth.”
It was believed that there is a natural progression of religion from worshiping gods who are personifications of natural forces to a supreme God who is not limited by nature. Thus coming from a Europe which had abandoned Caananite religions tainted by polytheism and idol worship, the Friar was shocked to see people worshiping “a dead idole, which, from the nauel vpward, resembleth a man, and from the nauel downeward an oxe.”
In the 18th and 19th century, an evolutionary model of religion was put forward in which polytheism was considered primitive, monolatry an improvement and monotheism, the purest form. Instead of understanding them as two different ways, a value judgment was passed. It was during that time that Thomas Macaulay and his friends came to India. For them the task was clear: the primitive practices had to be stopped and the natives had to be uplifted to the purest form.
Prof. Christine Hayes at Yale explains what happened next and how this evolutionary model of religion evolved into a r-evolutionary model. This is part of her course on Introduction to the Old Testament (Hebrew Bible) which explains how the Bible was in fact adapted from various Near East traditions. The course is no MMW4, but worth listening.