Side by side with these fanciful excursions into science, come more serious ones, as in the note on Algebra, which traces its progress since the year 1494, before which 'it had only arrived at the solution of problems of the second degree, inclusive.' A scrap of paper tells us that Casanova 'did not like regular towns.' 'I like,' he says, 'Venice, Rome, Florence, Milan, Constantinople, Genoa.' Then he becomes abstract and inquisitive again, and writes two pages, full of curious, out-of-the-way learning, on the name of Paradise: The name of Paradise is a name in Genesis which indicates a place of pleasure (_lieu voluptueux_): this term is Persian. This place of pleasure was made by God before he had created man. It may be remembered that Casanova quarrelled with Voltaire, because Voltaire had told him frankly that his translation of _L'Ecossaise_ was a bad translation. It is piquant to read another note written in this style of righteous indignation: Voltaire, the hardy Voltaire, whose pen is without bit or bridle; Voltaire, who devoured the Bible, and ridiculed our dogmas, doubts, and after having made proselytes to impiety, is not ashamed, being reduced to the extremity of life, to ask for the sacraments, and to cover his body with more relics than St. Louis had at Amboise. Here is an argument more in keeping with the tone of the _Memoirs_: A girl who is pretty and good, and as virtuous as you please, ought not to take it ill that a man, carried away by her charms, should set himself to the task of making their conquest. If this man cannot please her by any means, even if his passion be criminal, she ought never to take offence at it, nor treat him unkindly; she ought to be gentle, and pity him, if she does not love him, and think it enough to keep invincibly hold upon her own duty. Occasionally he touches upon aesthetical matters, as in a fragment which begins with liberal definition of beauty: Harmony makes beauty, says M. de S. P. (Bernardin de St. Pierre), but the definition is too short, if he thinks he has said everything. Here is mine. Remember that the subject is metaphysical. An object really beautiful ought to seem beautiful to all whose eyes fall upon it. That is all; there is nothing more to be said. At times we have an anecdote and its commentary, perhaps jotted down for use in that latter part of the _Memoirs_ which was never written, or which has been lost. Here is a single sheet, dated 'this 2nd September, 1791,' and headed _Souvenir_: