Toward a Robust Definition of Life: A Process-Based Framework Distinguishing Living Systems from Non-living Entities

This research explores the fundamental question of what constitutes life by proposing a rigorous, mechanistic definition and applying it to complex biological phenomena, including cancer cells. By examining the interplay between self-sustaining cellular processes and external support mechanisms, the study challenges conventional views on living systems, addressing debates around extreme parasites, immortalized lab cells, and artificially maintained organisms. Using a combination of theoretical reasoning and illustrative examples, the paper highlights how cells like cancerous or laboratory-maintained cultures straddle the boundary between autonomous life and externally dependent systems. Beyond its philosophical implications, this work provides a framework for understanding cellular behavior in biomedical contexts, offering insights relevant to oncology, synthetic biology, and bioethics. Ultimately, it invites researchers to reconsider the criteria for life, emphasizing both internal organization and interaction with environmental machinery.