1. Nyaya (Reasoning): It was founded by the ancient sage Gautama, it deals with logic which is the process of reasoning, Doubt is considered a prerequisite for philosophical inquiry.
2. Vaisheshika (Physical Sciences): It was developed by Prashastapada, it emphasizes the physical sciences such as chemistry, it includes exploring the elements of earth, water, fire, air and space, as well as time, mind and soul.
3. Samkhya (Framework of manifestation): It offers a framework for all the levels of manifestation, it comes from samyag akhyate: that which explains the whole.
4. Yoga (Practical methods for direct experience): It systematically deals with all of the levels of one's being, striving to experience the eternal center of consciousness, it involves systematic witnessing of one's inner states, so as to experientially go beyond all of them to the center of consciousness. It is often called Samkhya-Yoga, as it contains the practical methods to realize in direct experience the truths of Samkhya philosophy.
5. Mimasa (Freedom through action): It has a detailed philosophy related to ritual, worship and ethical conduct, which developed into the philosophy of karma.
6. Vedanta (Contemplative self-inquiry)