even if scientific practices of individuation vary from one scientificfield to
another, there often is a significant overlap between the questions and criteria
used by different biologists when they talk about biological individuals (Guay
and Pradeu 2016). This constitutes a promising research program for philoso-
phers of biology interested in making comparisons across several scientificfields.
In summary, the immune system plays a major role across species in deter-
mining the boundaries, constitution, and cohesion of the biological individual.
Far from the original concepts of self and nonself, today’s immunology tells us
that a living thing can be seen as an immunologically integrated chimera.
Although certainly not unique, the contribution of immunology to the long-
standing debate over biological individuality is important, so much so that
philosophers and biologists interested in that debate cannot neglect this contribu-
tion. What immunology has to say about individuality has long-reaching con-
sequences for our understanding of what a living thing is, including what we are
as humans, and it also impacts health issues of central importance, from auto-
immune and inflammatory diseases to antibiotic resistance and transplantation.
4 Cancer as a Deunification of the Individual
Cancer kills millions of people every year and is one of humanity’s greatest health
challenges. By stimulating the inherent ability of our immune system to attack
tumor cells this year’s Nobel Laureates have established an entirely new principle
for cancer therapy. Allison and Honjo showed how different strategies for inhibit-
ing the brakes on the immune system can be used in the treatment of cancer. The
seminal discoveries by the two Laureates constitute a landmark in ourfight against
cancer. (Excerpt of attribution of the 2018 Nobel Prize in Physiology or Medicine).“Why don’t we get more cancer?”asks Mina Bissell, a prominent specialist in
cancer (Bissell and Hines 2011). Certainly, most of us think that we do see
enough cancer around us. After all, approximately 90 million people had cancer
in 2015 (Vos et al. 2016) and cancer kills around 8.8 million people each year
(Wang et al. 2016). The 2014 World Cancer Report of the World Health
Organization estimated that there were about 14 million new cases of cancer
each year and that thefinancial costs of cancer were above US $1.16 trillion
per year. In this context, asking why we don’t get more cancer may seem
surprising if not shocking.
Yet Bissell’s question is entirely legitimate. We probably all have occult
tumors (Bissell and Hines 2011)–what Folkman and Kalluri called“cancer
without disease”(Folkman and Kalluri 2004). Autopsies of people dead due to
reasons unrelated to cancer reveal the high frequency of tumors, which can be
large but do not spread and do not seem to threaten the host. Prostate tumors can
be found in 30 to 70 percent of men over 60 years old, breast tumors in 7 to
Philosophy of Immunology 29