With the completion of his _Life of Goethe_, Lewes turned his attention more than ever to physiological studies, though he had continued to give them much attention in the midst of his other pursuits. In 1858 appeared his _Seaside Studies_, in which he recorded the results of his original investigations at Ilfracombe, Tenby, Scilly Isles and Jersey. This volume is written in a plain descriptive style, containing many interesting accounts of scenery and adventure, explanations of the methods of study of animal life at the seashore, how experiments are carried on, the results of these special studies, and much of controversy with other observers. It combines science and description in a happy manner. Another result of his physiological studies was a paper "On the Spinal Cord as a Centre of Sensation and Volition," read before the British Association for the Advancement of Science, in 1858. This was followed the next year by three published addresses on "The Nervous System," in which he presented those theories which were more carefully developed in his latest work, where he gave a systematic account of his philosophy. From this time on to his death the greater part of his energies were given to these studies, and to the building up of a philosophy based on physiology. A popular work, in which many of his theories are unfolded, and marked throughout by his peculiar ideas in regard to the relations of body and mind, was published in 1858. This was his _Physiology of Common Life_, a work of great value, and written in a simple, comprehensive style, suited to the wants of the general reader. In the first volume he wrote of hunger and thirst, food and drink, digestion, structure and uses of the blood, circulation of the blood, respiration and suffocation, and why we are warm and how we keep so. The second treats of feeling and thinking, the mind and the brain, our senses and sensations, sleep and dreams, the qualities we inherit from our parents, and life and death. In 1860 he printed in _The Cornhill Magazine_ a series of six papers on animal life. They were reprinted in book form in 1861, under the title of _Studies in Animal Life_. More strictly scientific than his _Seaside Studies_, they were even more popular in style, and intended for the general reader. While these books were being published he was at work on a more strictly scientific task, and one intended for the thoughtful and philosophic reader. This was his _Aristotle: a Chapter from the History of Science, including Analyses of Aristotle's Scientific Writings_, which was completed early in 1862, but not published until 1864. As in his previous works, Lewes is here mainly concerned with an exposition of his theories of the inductive method, and he judges Aristotle from this somewhat narrow position. He refuses Aristotle a place among scientific observers, but says he gave a great impulse towards scientific study, while in intellectual force he was a giant.