Despite its historical importance, relatively little attention has been paid to the theory of vital force that nineteenth century health reformers put forward. Allegedly, the vital force is a life-sustaining energy peculiar to living organisms, including human beings, and different from all the other forces found outside in non-living creatures. In this vein, this article examines ideas of vital force that Ellen G. White, one of the co-founders of the Seventh-day Adventists, maintained in her series of books called The Spirit of Prophecy. Also, this article shows the historical context of contemporary vitalism that presumably induced her to discourage masturbation (self-abuse or solitary vice as she called it) because ostensibly vital force could be expended by reckless ejaculation. She believed that devout Christians’ aim to maintain a holy body would be seriously thwarted by arbitrary semen leakage. For the purpose of comparative explanation, the article compares White’s ideas with those of Daoists. According to the Daoist Ge Hong (葛洪), an ancient Chinese thinker from the Wei-Jin period, in his book “Neipian” of Baopuzi (抱朴子), anyone can become an immortal Daoist hermit (神仙) by means of ancient chinese sexual arts (房中術) by which one should refrain from wastefully expending his semen (jing 精). Finally, this article discusses the relationship between semen loss and brain damage in the context of White’s masturbation taboo as well as Daoist semen-keeping arts called haijingbunao (還精補腦).