Samkhya

This term refers to a specific philosophical system rather than a general concept, making it a proper noun in most academic and spiritual contexts. It is typically used in scholarly discussions regarding Vedic traditions or the theoretical underpinnings of Yoga practice.

As a name for a specific school of thought, the word is treated as an uncountable noun. It does not take a plural form because it describes a singular, unified philosophical framework rather than a countable object or a category of items.