In response to the person who complained about the English translation of Candide featured in this book, I wish to point out a few things. Firstly, the French of the original version by Voltaire cannot be considered as 'modern,' even though it is perfectly understandable to the modern reader. There are a few archaic touches here and there, sometimes because the language has evolved, sometimes because Voltaire intended it so (e.g. the title of the first chapter, "et comment il fut chassé d'icelui" > "and how he was driven thence", or something like that, was archaic even for Voltaire). I find the English translation fairly accurate in that respect. This is the opinion of a native French speaker, though.
Secondly, and consequently, the use of 'thou' in the translation is understandable. This is not the 'clerical' thou as can still be read in the English Bible and other 'flavoured' translations, but the older 'thou', which had become in Late Middle English the familiar, even contemptuous form of the deferential pronoun 'ye' (originally exclusively plural). The 'clerical' thou is a relatively modern device used in certain type of writings to convey an archaic language, but it is really an 'invention.' Therefore, the use of 'thou' in Candide, where the French has the familiar form 'tu,' is acceptable ; but it certainly can be misleading to the modern reader.
That is not to say this is the perfect translation -- such a thing does not exist. Where Voltaire uses understatement to great comic effect I find the translator usually too emphatic. Also the French version is much more vulgar in places. I suppose this translation is quite old ; there are others, but I did not read them.
To those considering purchasing or reading this book: do so, by all means. Candide is a thought-provoking, entertaining and humorous tale for readers of various tastes. It is a classic.