Final answer:
James Firth Stephenson stated that the presence of a neurological component is necessary to define a condition as a subluxation.
Step-by-step explanation:
James Firth Stephenson, a 1921 graduate of the Palmer School of Chiropractic, insisted that a neurological component must exist to qualify the condition as a subluxation. In chiropractic theory, a subluxation is a misalignment of the vertebrae that affects nerve communication and can lead to various health issues. However, it's worth noting that the concept of subluxation and its clinical implications are subjects of debate within the medical community, with some viewing them as lacking sufficient empirical evidence.