Abstract: This article proposes that Homo sapiens possess five interrelated yet irreducible ontological characteristics:positive feedback dynamics,looping,ad-hocness,tail-heaviness,and a small-group animal nature.Together,these features constitute what I term sapiensity.The article traces the intellectual development of this concept across nearly half a century of my scholarly inquiry and situates it within the broader structural-mechanism-evolutionary trajectory of material development since the formation of the Earth.It further argues that sapiensity should serve as a new ontological foundation for philosophy and the social sciences.The article also contends that,in the age of accelerating technological and social change,the structural tensions inherent in sapiensity are amplified to an unprecedented degree,significantly heightening the systemic risks facing human societies.In response,it advances a utopian proposal centered on curbing excessive concentrations of social power.It argues that,given the irreducibility of sapiensity,this may be the only logically coherent pathway through which humanity can avoid being drawn into runaway structural dynamics of its own making—and ultimately becoming unable to extricate itself from them.