I can provide you with another example, if you like.

I am currently typing this response to you on my computer. But in order for me to be able to do this, my fingers must be tapping on the keyboard. But in order to do this, my muscles must be moving my fingers. But in order to do this, my nerves must be stimulating my muscles. But in order to do this, my brain is directing my nerves.

If I remove either the first mover in this series, my brain, or any of the instrumental movers, then this comment could not exist. This is a series in which everything that is moved is dependent on the previous mover. Everything in between the first and last member of the series is an instrument of the first mover; in other words, it is really my brain which is writing the comment, through the nerves, the muscles, the fingers, and the keyboard.

Does that make sense?