Definition of "non-self"

Signs are inherent in the various aspects of the immune system which differentiate self from non-self.

2009, Bill Whitehouse, Meditations of a Sufi‎

For the artificial immune system, the recognition of the non-selfs is classified into two types according to the difference among the non-selfs, and the two approaches for recognizing the non-selfs are inspired from the innate immunity and the adaptive immunity in the biological immune system.

2009, Hongwei Mo, Handbook of Research on Artificial Immune Systems and Natural Computing […] ‎

[W]e could at least begin to answer the question, What is self? by referring to some paradigm cases of selves . . and some paradigm case of non-selves.

2013, Shaun Gallagher, Models of the Self‎