Merritt Gardner Kellogg (1832–1921) was a Seventh-day Adventist physician and medical missionary. M.G. Kellogg was closely associated with Ellen G. White. In 1906, he revealed that Ellen White's visions were not divine, but were the result of a medical condition called Catalepsy:
M.G. Kellogg also documented the malicious attack against his brother J.H. Kellogg by SDA leaders and Ellen G. White. The documentation shows that Ellen White used fraud and deception in an attempt to crush Dr. Kellogg because he would not give her the money she asked for.