The Bell-Magendie Law established that different nerves transmit different types of information (e.g., sensory vs. motor).
Building upon this foundational principle, scientist Johannes Müller proposed the doctrine of specific nerve energies.
This doctrine states that the quality of sensation experienced depends not on the type of stimulus or the nerve stimulated, but on the specific nerve pathway activated. For instance, stimulating the optic nerve results in a visual sensation, regardless of whether the stimulus is light or electrical. Müller's work significantly expanded the understanding of sensory pathways and perception.
Therefore, Johannes Müller devised the doctrine of specific nerve energies by expanding the Bell-Magendie Law.