A large part of this mass consists of the correspondence of which we are making such frequent use in these chapters. Letter-writing is perhaps the most pleasing and genuine of all the literary activities of the time; men took pains to write well, yet not with any definite prospect of publication, such as was the motive a century later in the days of Seneca and Pliny. The nine hundred and odd letters of the Ciceronian collection are most of them neither mere communications nor yet rhetorical exercises, but real letters, the intercourse of intimate friends at a distance, in which their inmost thoughts can often be seen. Cicero is indeed apt to become rhetorical even in his letters, when writing under excitement about politics; but the most delightful letters in the collection are those in which he writes to his friends in happy and natural language of his daily life and occupations, his books, his villas, his children, his joys and sorrows. It is strange that the great historian of Rome in our time entirely failed to see the charm and the value of these letters, as of all Cicero's writings; his countrymen have now agreed to differ from him, and to restore a great writer to his true position. In philosophical receptivity too the brightest and finest minds among this aristocracy show an ability which is almost astonishing, when we consider that there had been no education in Rome worth the name until the second century B.C.[170] I use the word receptivity, because the Romans of our period never really learnt to think for themselves; they never grappled with a problem, or struck out a new line of thought. But so far as we can judge by Cicero's philosophical works, the only ones of his age which have come down to us, the power to read with understanding and to reproduce with skill was unquestionably of a high order. The opportunities for study were not wanting; private libraries were numerous, and all Cicero's friends who had collected books were glad to let him have the use of them.[171] Greek philosophers were often domesticated in wealthy families, and could discourse with the statesman when he had leisure from public business. Much of this was no more than fashion, and real endeavour and earnestness were rare; but the fact remains that one philosophical system, more especially on its ethical side, took real possession of the best type of Roman mind, and had permanent and saving influence on it.