The Classic Definition of Life

The coconut octopus (Amphioctopus marginatus)

[The coconut octopus (Amphioctopus marginatus) satisfies the classic definition of life. Photo: Nick Hobgood. Source: Wikipedia.]

My friend, student, and coworker David Wicksell has pointed out that in my writing I use terms like "alive" and "living system" without specifying what I mean. Am I using these terms metaphorically, or do I somehow mean that VISTA is actually alive?

He raised this question because in Tuesday's webinar, An Introduction to VISTA Architecture, I said it's not a metaphor, that VISTA's literally alive - but how can that be true? Software is part of a machine, so how can it be alive? I agreed with him that I'm long overdue to spend some time laying out what I mean by these loaded terms.

The problem with calling VISTA alive is that it does not appear to satisfy the classic definition of life. I quote at length here from Wikipedia, whose article Definition of Life contains pretty much the definition I was first exposed to back in high school, and that most biology textbooks use:

Since there is no unequivocal definition of life, the current understanding is descriptive, where life is a characteristic of organisms that exhibit all or most of the following phenomena:


1. Homeostasis: Regulation of the internal environment to maintain a constant state; for example, electrolyte concentration or sweating to reduce temperature.


2. Organization: Being structurally composed of one or more cells, which are the basic units of life.


3. Metabolism: Transformation of energy by converting chemicals and energy into cellular components (anabolism) and decomposing organic matter (catabolism). Living things require energy to maintain internal organization (homeostasis) and to produce the other phenomena associated with life.


4. Growth: Maintenance of a higher rate of anabolism than catabolism. A growing organism increases in size in all of its parts, rather than simply accumulating matter.


5. Adaptation: The ability to change over a period of time in response to the environment. This ability is fundamental to the process of evolution and is determined by the organism's heredity as well as the composition of metabolized substances, and external factors present.


6. Response to stimuli: A response can take many forms, from the contraction of a unicellular organism to external chemicals, to complex reactions involving all the senses of multicellular organisms. A response is often expressed by motion, for example, the leaves of a plant turning toward the sun (phototropism) and by chemotaxis.


7. Reproduction: The ability to produce new individual organisms, either asexually from a single parent organism, or sexually from two parent organisms.

One may quibble about terms or ideas here or there, but overall most biologists would agree that this is the current working definition of a living organism, more or less.

Does VISTA satisfy this definition?