It was amid such surroundings that the _Academica_ was written. The first trace of an intention to write the treatise is found in a letter of Cicero to Atticus, which seems to belong to the first few weeks of his bereavement[138]. It was his wont to depend on Atticus very much for historical and biographical details, and in the letter in question he asks for just the kind of information which would be needed in writing the _Academica_. The words with which he introduces his request imply that he had determined on some new work to which our _Academica_ would correspond[139]. He asks what reason brought to Rome the embassy which Carneades accompanied; who was at that time the leader of the Epicurean school; who were then the most noted πολιτικοι at Athens. The meaning of the last question is made clear by a passage in the _De Oratore_[140], where Cicero speaks of the combined Academic and Peripatetic schools under that name. It may be with reference to the progress of the _Academica_ that in a later letter he expresses himself satisfied with the advance he has made in his literary undertakings[141]. During the whole of the remainder of his sojourn at Astura he continued to be actively employed; but although he speaks of various other literary projects, we find no express mention in his letters to Atticus of the _Academica_[142]. He declares that however much his detractors at Rome may reproach him with inaction, they could not read the numerous difficult works on which he has been engaged within the same space of time that he has taken to write them[143].