The Charvaka, Nyaya-Vaisesika and Sankhya philosophies (the three philosophies placed under the category of 'Anviksiki' or Logic based, rational philosophies by Kautilya in his Arthasastra) represent the hard core of the antithesis of Indian idealism. These three philosophies--in their original form--are characterised by secularism, rationalism and science orientation. Secondly, these philosophies not only defend the reality of the material world or nature, but work moreover for an essentially materialist interpretation of its constitution, based on their respective theories of matter, nameley the bhutas (physical elements), pradhana or prakriti (primieval matter) and paramanu-s (atoms).
In all of these three philosophies, the ontological status of consciousness--compared to matter--is distinctly secondary. In the case of the Charvakas, this is quite obvious. In the case of the Sankhyas, we can see this after certain clarifications. Lastly, according to the Nyaya-Vaisesikas, though matter, in the form of atoms, is eternal and immutable, consciousness is essentially a transient phenomenon, somehow or other temporarily produced by the peculiar collocation of a number of intrinsically unconscious (jada) entities, most of which are material.
Of course,the Nyaya-Vaisesika themselves have no clear answer to to the question of how the essentially unconscious entities can produce consciousness, but their philosophical position demands that this has to be so. In the Sankhya philosophy, we have a hazy view of an attempt at a theoretical understanding of the origin of consciousness from matter. But the boldest explaination of this possibility is to be found in the view of Lokayata/Charvaka which, though the most neglected of all Indian philosophies, has from this point of view a unique interest in the history of Indian thought.
Let us turn to the Nyaya-Vaisesika first.
It is especially significant to note that the view of the 'soul' and consciousness, as found in the earliest available Nyaya-Vaisesika texts, appear somewhat bewildering to modern orthodoxy oriented scholars. It is evidently a view of the soul with a peculiarly materialist nuance. In other words, the Nyaya-Vaisesika view of the soul--and therefore also of the phenomenon of consciousness related to it---seems to have a materialist basis.
A convenient starting point for understanding the Nyaya-Vaisesika view of soul and consciousness is to compare it to the view of the same held in the Advaita Vedanta.
[To be continued]