The six systems of Indian philosophy, known as the "Shad Darshanas," include Nyaya, Vaisheshika, Sankhya, Yoga, Mimamsa, and Vedanta, each representing distinct metaphysical and epistemological approaches. Lokayata, also known as Carvaka, is a materialistic and atheistic school that rejects the spiritual and metaphysical insights of the orthodox systems, while Kapalika refers to an esoteric sect within Shaivism with a focus on ritual and asceticism, rather than a systematic philosophical treatise. Since neither Lokayata nor Kapalika aligns with the structured frameworks of the accepted six schools, they do not form part of the classical Indian philosophical canon as recognized in UPSC syllabus and standard texts.