signal as a fixed setpoint of acceptable values, and an error signal calculated by a comparator that is what helps determine the output. The process through which we determine the output is negative feedback loops, where the organism determines if the output was able to reduce the error signal and if it was not the organism is able to set forth a new output through hierarchical control systems. These concepts are essential for the understanding of Mayr’s claim.
Mechanists believe in linear causation and argue that animals and other complex living systems do not have any form of consciousness or intentionality in their actions and the only material forces that act upon them are those that are physico-chemical. However, Mayr claims that these same scientists disagree with the idea that animals are nothing but machines, thus Mayr argues that since the explanations that only use physical sciences oversimplify complex living systems that the most precise way to comprehend them is through negative feedback. This oversimplification comes to light in the theory of the “calculation problem” which is the idea that the output of the final common path must always vary according to the changes introduced by the unknown disturbances. Thereby, if the source of these disturbances is unpredictable, the brain would not be able to decipher how much output to produce and when. Hence, the argument of linear causation would be discredited because we could not have the input precede the output. On the contrary, negative feedback takes into consideration that complex living systems do have the level of consciousness necessary to generate goal-corrected behaviors and thus be able to, through negative feedback loops, stabilize their error signals and ultimately control their behavior through output. In conclusion, due to the calculation problem and the limitations of linear causation, we cannot assume complex living systems are merely machines and thus, negative feedback loops provide the most precise explanation for their complex behaviors.