We find him at Turin in November, 1716, with a fresh leave of absence for two years from his College. It seems that Ashe, Bishop of Clogher, had engaged him as travelling tutor to his son, a means not then uncommon for enabling young authors of moderate fortune to see new countries and mix with society. Addison had visited Italy in this way sixteen years before, and Adam Smith long afterwards travelled with the young Duke of Buccleuch. With young Ashe, Berkeley crossed Mont Cenis a second time. They reached Rome at the beginning of 1717. His _Journal in Italy_ in that year, and occasional letters to Percival, Pope, and Arbuthnot, shew ardent interest in nature and art. With the widest views, “this very great though singular sort of man descended into a minute detail, and begrudged neither pains nor expense for the means of information. He travelled through a great part of Sicily on foot; clambered over the mountains and crept into the caverns, to investigate its natural history and discover the causes of its volcanoes; and I have known him sit for hours in forges and foundries to inspect their successive operations(11).” If the _Journal_ had been transformed by his own hand into a book, his letter to Pope from Inarime shews that the book might have rivalled Addison’s _Remarks on Parts of Italy_ in grace of style and large human interest. In the summer of 1720 we find the travellers at Florence, afterwards for some time at Lyons, and in London at the beginning of the next year. On the way home his metaphysical inspiration was revived. The “Cause of Motion” had been proposed by the French Academy as the subject of a prize dissertation. The subject gave an opportunity for further unfolding his early thought. In the _Principles_ and the _Dialogues_ he had argued for the necessary dependence of matter, for its concrete substantial reality, upon living percipient mind. He would now shew its powerlessness as it is presented to us in sense. The material world, chiefly under the category of substance, inspired the _Principles_. The material world, under the category of cause or power, inspired the _De Motu_. This Latin Essay sums up the distinctive thought of Berkeley, as it appears in the authorship of his early life. _Moles evolvit et agitat mentes_ might be taken as the formula of the materialism which he sought to dissolve. _Mens percipit et agitat molem significantem, cujus esse est percipi_ expresses what Berkeley would substitute for the materialistic formula.