The usual meaning of "purpose" is, I suppose, something like "the aim of an intelligent agent".
Thus, an individual might do things for certain purposes. My purpose in poking at this keyboard is to communicate with you and others who may be following this thread.
I may be missing something, but it doesn't seem to make sense to talk about the purpose of all life, including the life of a simple organism, unless one is talking about the aim the creator, God, had in creating life.
I understand that you do not believe in God. Thus, I can't make any sense of your reference to "purpose" with respect to the life of a simple organism. What do you mean by the word?
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I understand that you do not believe in God. Thus, I can't make any sense of your reference to "purpose" with respect to the life of a simple organism. What do you mean by the word?
With regard to rational beings, purpose means just what you have indicated, one's intention, or goal, or "aim." But the word also is used of any action that has a specific result.
Life is a self-sustained process. It is at once both the means and the end. Since life does not exist independently of living organisms, and to sustain itself, the life process must sustain itself as an organsim, the purpose of the life of an organism is to sustain the organism.
But notice, to sustain itself, an organism cannot do just anything. What it must do to survive is determined by the nature of the organism. Except for man, organisms that are not defective always act in the way their nature requires. The automatic pattern of behavior non-rational organisms are provided by their nature is called instinct.
I understand that you do not believe in God, is a presumption. I do not know what you mean by God. Who knows, I might believe in God, if a rational (understandable) definition, without floating abstractions and stolen concepts were provided.
Hank