Jean-Jacques Rousseau (1712–1778) is the author of numerous political and philosophical texts as well as entries on music for Diderot's Encyclopédie and the novels La nouvelle Héloïse and Émile.
J. M. Cohen, born in London in 1903 and a Cambridge graduate, was the author of many Penguin translations, including versions of Cervantes, Rabelais and Montaigne. For some years he assisted E. V. Rieu in editing the Penguin Classics. He collected the three books of Comic and Curious Verse and anthologies of Latin American and Cuban writing. He frequently visited Spain and made several visits to Mexico, Cuba and other Spanish American countries. With his son Mark he edited the Penguin Dictionary of Quotations and its companion Dictionary of Modern Quotations.