_Editio Princeps_: The first edition of the _de Officiis_ was from the press of Sweynheim and Pannartz at the Monastery of Subiaco; possibly the edition published by Fust and Schöffer at Mainz is a little older. Both appeared in 1465. The latter was the first to print the Greek words in Greek type. The _de Officiis_ is, therefore, the first classical book to be issued from a printing press, with the possible exception of Lactantius and Cicero's _de Oratore_ which bear the more exact date of October 30, 1465, and were likewise issued from the Monastery press at Subiaco. _Baiter & Kayser_: M. Tullii Ciceronis opera quae supersunt omnia. Lipsiae, 1860-69. _Beier_: M. Tullii Ciceronis de Officiis libri tres ... cum commentariis editi a Carolo Beiero. Lipsiae, 1820. _Erasmus_: } M. Tullii Ciceronis Officia, diligenter restituta. _Melanchthon_: } Ejusdem de Amicitia et Senectute dialogi...: cum annotationibus Erasmi et P. Melanchthonis. Parisiis, 1533. _Ed._: M. Tullii Ciceronis Scripta quae manserunt omnia recognovit C. F. W. Müller. Teubner: Lipsiae, 1879. This edition is the basis of the text of the present volume. _Ernesti_: M. Tullii Ciceronis opera ex recensione novissima. J. A. Ernesti; cum eiusdem notis, et clave Ciceroniana. Editio prima Americana. Bostoniae, 1815-16. _Facciolati_: M. Tullii Ciceronis de Officiis libri tres, de Senectute, de Amicitia, de Somnio Scipionis, et Paradoxa. Accedit Q. fratris commentariolum petitionis. Ex recensione J. Facciolati. Venetiis, 1747. _Fleckeisen, Alf._: Kritische Miscellen. Dresden, 1864. _Gernhard_: M. Tullii Ciceronis de Officiis libri tres. Rec. et scholiis Iac. Facciolati suisque animadversionibus instruxit Aug. G. Gernhard. Lipsiae, 1811. _Graevius_: M. Tullii Ciceronis de Officiis libri tres; ... de Senectute; ... de Amicitia; Paradoxa; Somnium Scipionis; ex recensione J. G. Graevii. Amstelodami, 1689. _Gulielmus_: } M. Tullii Ciceronis opera omnia quae extant ... _Gruter_: } emendata studio ... J. Gulielmi et J. Gruteri. Hamburgi, 1618-19. _Heine, Otto_: M. Tullii Ciceronis de Officiis ad Marcum Filium Libri tres. 6te Aufl. Berlin, 1885. _Heusinger_: M. Tullii Ciceronis de Officiis libri tres ... recensuit adjectisque J. M. Heusingeri e suis annotationibus ... editurus erat J. F. Heusinger. (Edited by C. Heusinger.) Brunsvigae, 1783. _Holden_: M. Tullii Ciceronis de Officiis libri tres, with Introduction, Analysis and Commentary by Herbert Ashton Holden. 7th Edition. Cambridge, 1891. To his full notes the translator is indebted for many a word and phrase.