My presentation of a general theory of living systems will employ two sorts of spaces in which they may exist, physical or geographical space and conceptual or abstract space...
The characteristics and constraints of physical space affect the action of all concrete systems, living and nonliving... Physical space is a common space because it is the only space in which all concrete systems, living and nonliving, exist (though some may exist in other spaces simultaneously). Physical space is shared by all scientific observers, and all scientific data must be collected in it. This is equally true for natural science and behavioral science.

p. 9-10; As cited in: Kenneth D. Bailey (1994) Sociology and the New Systems Theory: Toward a Theoretical Synthesis. p. 262 - Living systems, 1978