brain, which only controls conscious activity. Laycock disagreed with Unzer's centralisation in the spinal root ganglia; Laycock stated: "The brain, although the organ of consciousness, was subject to the laws of reflex action and in this respect it did not differ from other ganglia of the nervous system." Nature and methodology Laycock was a teleologist. He also held a fundamental belief in the "unity of nature", and saw nature as working through an unconsciously acting principle of organisation. Through his teleological approach, he argued that the origins of the nervous system were based on a natural force which he named the "Unconsciously Acting Principle for Intelligence." This force provided a plan for organism construction, regulated organisms based on survival instinct, and acted on the brain to provoke the phenomena of thought. Laycock saw nature as purposeful in creating this force, which ultimately results in a self-conscious mind, and an unconscious intelligence where reflexes were seeded. Because of his teleological approach to seeing nature through a lens of purpose, Laycock used observation as his principal method of scientific inquiry. He did not advocate for microscopic experimentation, which he saw as unnecessary in studying nature's biological forces. Rather, he preferred passive observation of purposeful phenomena in nature, from which theories could be inducted. Classification of psychiatric disorders In 1863, Laycock published a paper on the classification of psychiatric disorders. On the classification, he said: "If we further analyse the standard as applied to the naming and classification of mental diseases in general, we find it includes attributes or qualities in common with others of the same age, sex, or social position". Laycock recognised that many factors were included in classification, and therefore absolute standards were not feasible. Laycock was also aware of the different possible approaches in classification, but he used a biological and neurological approach to classification. He classified insanity into three types: orectic insanity, thymic insanity, and phrenic insanity. Each type of insanity was associated with a disorder in encephalic centers that controlled instincts, feelings, or reason. The biological approach to classifying mental disorders was due to Laycock's belief that the mind was a result of the brain. On insanity, his definition was: "a chronic disorder of the brain by which the mental condition of the individual is so modified that he is deprived wholly or in part of common sense." He explained moral insanity and mania through the concept