As Sydenham notes, The strength and constancy of mind, as long as it is confined in the body, much depends on the firmness of the spirits that are subservient to it; which indeed are made of the finest matter, and are placed in the confines of material beings; and as the frame of the mind, if it be lawful to call it so, is much more curious and delicate than the structure of the body, for it consists in the harmony of the most excellent and almost divine faculties; so if the constitution is any way vitiated, by so much the greater is the ruin, by how much it was more excellent and more exquisitely composed when it was whole.