I got this article forwarded to me on email, and I find it to be a very good one, one that traces the origins of the Vedanta schools of Hindu philosophy. Before posting the article, a brief overview. Vedanta literally means "End of the Vedas" (Also interpreted as the "Culmination of the Vedas").
The Vedas were Hindu hymns from around 2000 BC which talk about pretty much everything under the sun. Even though the core of the Vedanta philosophies already existed in the Vedas, they were simply overwhelmed by the ritual so commonly found in the Vedas. Thus by around 2000-1500 BCE Hinduism has become entirely dependent upon rituals and worship of the god/s (except for a select few who chose the paths of Yoga(meditation) and Jana(knowledge)).
These Yogis(Those who practiced Yoga) and Janis(Those who sought knowledge..be is spiritual or scientific) were disgusted by the ritualism they saw around them..and brought about a revolution by writing/collating a series of works known as the Upanishads(also known as Vedanta). Some were pure materialists...some were scientists..some Atheists, some agnostics....Atomists...men and Women who decided that the rigorous ritual and worship of the god/s do not lead to any positive end and took it upon themselves to rid Hinduism of the Vedic Ritualism. Their work gave Hinduism some of its most lofty and sublime philosophical traditions, especially the non-dualist philosophies(Advaita Vedanta) which pretty much eliminated most of the Vedic ritualism and the Vedic pantheon.