Kôkaku Kidôtai1995

Puppet Master:
I refer to myself as an intelligent life form because I am sentient and I am able to recognize my own existence, but in my present state I am still incomplete. I lack the most basic processes inherent in all living organisms: reproducing and dying.

Major Motoko Kusanagi:
But you can copy yourself.

Puppet Master:
A copy is just an identical image. There is the possibility that a single virus could destroy an entire set of systems and copies do not give rise to variety and originality. Life perpetuates itself through diversity and this includes the ability to sacrifice itself when necessary. Cells repeat the process of degeneration and regeneration until one day they die, obliterating an entire set of memory and information. Only genes remain. Why continually repeat this cycle? Simply to survive by avoiding the weaknesses of an unchanging system.