The philosophy of samkhya also refers to gunas (innate qualities or tendencies) that we all have, which cover the likes of good, chaotic and destructive behavior. It is how these gunas interact in each person that defines their character.
In terms of yoga practice, this is an important term to bear in mind while meditating. Knowledge of the duality of samkhya can allow the practitioner to understand the world around them and how they form part of it. In a way, it also shows how different parts of a human work and the functions they carry out.