“There is, therefore, both positive and negative proof in favour of my mental and suggestive theory, and in opposition to the magnetic, occult, or electric theories of the Mesmerists and electro-biologists. My theory, moreover, has this additional recommendation, that it is level to our comprehension, and adequate to account for all which is demonstrably true, without offering any violence to reason and common sense, or being at variance with generally admitted physiological and psychological principles.”