Since 2000, the possibility of extending human lifespan has been a highly debated topic by both biomedical scientists (de Grey and Rae, 2007; Olshansky & Carnes, 2002) and philosophers (Agar, 2010; Overall, 2003). One kind of attempt to find middle ground in this debate has been efforts to distinguish two kinds of life extension: moderate and radical (Agar, 2013; Glannon 2002; Lucke et al, 2006). Although, there are three reasons for rejecting this distinction:
1. The difference between moderate and radical life extension cannot be explained only by a quantitative measurement but also by a qualitative distinction. Jeanne Calment's age is not a maximum lifespan (imaginable) and I propose the concept of Uncertainty Threshold of Longevity to debate whether there is a limit in our species.
2. The question of whether a therapy will be considered in a Weak Sense or in a Strong Sense. It still does not exist, save (or with the exception of) caloric restriction, many promising researches on aging. How to evaluate whether a treatment will add more years or more health or how to know the best way to live 200 years?
3. A thought experiment named Peter Pan Drug suggests that a healthspan extension, in a radical sense, allows us to re-think about a lifestyle totally different from now. Example: a life extended to 120 years but maintaining physical and mental condition all the time, is it moderate kind?
I propose an alternative model for resolving this debate. This model builds upon the distinctions that Juengst (et al, 2003) and Wareham (2016) make about different levels and means to control human senescence, to propose the following conceptual categories: (a) Compression of Morbidity; (b) Slowed Aging; (c) Negligible Aging or SENS; (d) Arrested Aging; (e) Escaping Aging. In addition, I have to add several concepts which are relevant for my purpose: indefinite life, virtual sort of immortality or (true) immortality.