From the following paragraph, why would the input or the initial condition not matter in the output?

On pg.37 of “Principles of Neural Science,” they state that “…in systems with feedback circuits it is the dynamic activity of the system that determines the outcome of computation, not inputs or initial conditions” (37). What do they exactly mean in this sentence?
I apologize for the follow-up question, but how would a feedback connection even look in a neural network?