As our intrinsic subjective experience, pain possesses the following distinct characteristics: intrinsic direct relevance, subjectivity, and crosssubjective shareabilityThe intrinsic subjective sensation is the fundamental characteristic of qualiaIt cannot be reduced to its various external manifestationsQualia are our intrinsic subjective sensations, but this does not mean that they are private and unique to each individualOn the contrary, qualia can be shared across subjectsThe crosssubjective shareability of qualia forms the true foundation of human social communitiesThe subjectivity of sensation is a product of biological evolution, through which, life has acquired the capacity for subjective sensations, even selfawareness, and so forthSuch capacity constitutes a new mode of existence for life, and reestablishes the foundation for the existence of living beings.