Are there any individual cells that make decisions, or do they all react to their immediate environments according to chemical and mechanical laws?
In other words, is there any individual cell that can decide between two or more options, or all they all solely chemical and mechanical reactions without any self-determination at all?
"self-Determination" and "decision-making" are conscious, complex processes. A single cell is incapable of that.
On the other hand, how do we as humans form decisions? We use sensory input from various organs, process those by combining with existing knowledge/memories and form decisions based on that. But in the end, it's still all based on "chemical and mechanical reactions".
You quickly get into philosophical territory there: is our conscious self more than the sum of all the processes in our brain? Is there some extra "spark" that allows true self-determination, or are all our decisions a given result of the exact state of our brain and body?
I think that the illusion of free will is based on the fact that we're conscious and thus have preferences and since decisions naturally tend to align with said preferences it then feels like we're in control. However, nobody chose their likes and not-likes.
I think Brian Greene put it nicely; we don't have free will but we have the experience of freedom
I think you're projecting consciousness onto those terms more than you need to. An algorithm is a decision-making process devoid of consciousness (as far as we know). AI is capable of self-determination in as far as it's capable of acting without reacting, or without total dependence on input. We just need our self-determination and decision-making to be special, so we present them as functions of our consciousness.
And a curse on any philosopher that tries to define consciousness as some variation of "that thing that makes human special", any work they build on that is doomed.