Ānvīkṣikī is a term in Sanskrit denoting roughly the "science of inquiry" and it should have been recognized in India as a distinct branch of learning as early as 650 BCE. However, over the centuries its meaning and import have undergone considerable variations. In the earliest period, the term was used to denote Atma-vidya, the science of the soul, in contrast to Adhyatma-vidya, the spiritual science, or Brahma-vidya, the divine science. In Manu Smriti the term Ānvīkṣikī has been used as equivalent to Atma-vidya and it has been described as a branch of the Vedas. In the fourth century BCE, Kautilya in his Arthashastra recognised it as a distinct branch of learning different from Vedas and other disciplines. Kautilya classifies all disciplines into four categories: scripture (the three Ved