Clouds and warm rain. At home all day in study. Evening at the Mansion.

Continued Locke’s Essay 300–352. Chapter of Identity and Diversity. The line between things comprehensible and things not so is so thin that it is very difficult to keep exactly within the former. All identity springs from consciousness, says Mr. Locke, but then of what are we conscious? for all ordinary purposes we have clearer evidence than consciousness in the fact of existence in a shape readily cognizable by the senses, and for extraordinary ones what do we gain by changing the word.

Lucretius, finished the third book and read 100 lines in the fourth. On the whole the conclusion of the third book is most of all to my taste. Had Lucretius grappled with a subject more susceptible of the introduction of the graces, he would have scarcely been exceeded by his borrower Virgil. But philosophical abstractions are a potion the bitterness of which to most readers no honey of poesy can make palatable.

Finished the first Chapter of Winkelman’s History of Art, which did not interest me. Also one or two Chapters in Bayle’s Réponse aux questions d’un provincial, which led me to examine in the Causes Cé-114lèbres the curious case of Martin Guerre.1 Nothing new from the conversation of the evening.