Vedic traditions were not accessible to the common public and only came through Brahmins, who claimed to have an inherited and divine authority on the matter. For instance, according to scriptures such as the Manu Smriti, a Vaisya (merchant class) or a Sudra (untouchable) could not become a “Chaturvedi” even if they read all four Vedas. It had to be a Brahmin man, and the Manu Smriti provides extremely rigorous and painful rules and traditions for becoming a Brahmin—it starts with inheritance and birth. Thus, around the 7th or 6th century BCE, some atheistic schools of thought emerged in the Indian subcontinent. This era was marked by the advent of the Sramana (or Samana) movement—a sort of heterodox philosophical shift away from traditional gatekept Vedic ritualism, also known as Brahminism. These opposing ideas included Charvaka, Ajivika, Agyana, Jainism, and Buddhism. They were not designed to be gatekept by a lineage of elites and were accessible to all regardless of caste or class. Buddhism and Jainism stood out among atheistic Sramana thought and became more popular, spreading further as they received endorsement from powerful kingdoms (for example, the Maurya king Ashok adopting and evangelizing Buddhism) and influential merchant classes. But Charvaka, Ajivika, and Agyana are not as well-known because their original texts perished gradually around the medieval era, though recollections and discussions of them exist in later secondary Hindu, Buddhist, and Jain texts. In this blog, I will focus only on Charvaka, Ajivika, and Agyana philosophy. Buddhist, Jain, and Samkhya ideas deserve their own blogs.