The 19th-Century Trippers Who Probed the Mind.

In the 19th century, scientists engaged in self-experimentation with mind-altering drugs to explore the limits of subjectivity. This approach was rooted in the belief that direct evidence and first-person observation were necessary for scientific truth. Scientists like Isaac Newton and Robert Boyle conducted experiments on themselves to understand the effects of drugs on the mind. These experiences, although subjective, provided unique insights into mental functioning. The language used to describe these experiences was influenced by medicine, and self-experimentation with drugs was common practice among physicians. The experiments of chemist Humphry Davy with nitrous oxide led him to develop a "language of feeling" to describe the effects of the gas. This language collapsed the distinction between the intellect and the passions and raised questions about the relationship between mind and body. Davy's groundbreaking report on his experiments linked the chemical, medical, and sublime aspects of the experience. [Extracted from the article]