The prevailing biology of the modern era describes life as a system. A system is defined a set of things working together as parts of a mechanism or an interconnecting network. The NASA definition of life is this: “Life is a self-sustaining chemical system capable of Darwinian evolution”
However, I think there is a problem with this.
A living thing is understood as a being whose parts work together for one goal, which is the sustainment of the whole organism. In this sense, the parts comprise truly one being, as this principle that unites the parts is intrinsic to the organism.
However, a machine is not a one being as much as a heap of sand is not a one being, as its goal, function is imparted from the outside. Its principle of unity is extrinsic, its unity is in the perceiver's mind, not in-itself.
Therefore, we can say that a machine is only a metaphor, something that resembles life but not quite. Machine or a system is built to mimic life.
If this is the case, isn't defining life by something that mimics life problematic?