concourse of corpuscules, for this is the name he gives to atoms. You know our system of natural philosophy, which depends upon the two principles, the efficient cause, and the subject matter out of which the efficient cause forms and produces what it does produce. For we must have recourse to geometry, since, if we do not, in what words will any one be able to enunciate the principles he wishes, or whom will he be able to cause to comprehend those assertions about life, and manners, and desiring and avoiding such and such things? For those men are so simple as to think the good of a sheep and of a man the same thing. While you know the character and extent of the accuracy which philosophers of our school profess. Again, if you follow Zeno, it is a hard thing to make any one understand what that genuine and simple good is which cannot be separated from honesty; while Epicurus asserts that he is wholly unable to comprehend what the character of that good may be which is unconnected with pleasures which affect the senses. But if we follow the doctrines of the Old Academy which, as you know, we prefer, then with what accuracy must we apply ourselves to explain it; with what shrewdness and even with what obscurity must we argue against the Stoics! The whole, therefore, of that eagerness for philosophy I claim for myself, both for the purpose of strengthening my firmness of conduct as far as I can, and also for the delight of my mind. Nor do I think, as Plato says, that any more important or more valuable gift has been given to men by the gods. But I send all my friends who have any zeal for philosophy into Greece; that is to say, I bid them study the Greek writers, in order to draw their precepts from the fountain-head, rather than follow little streams. But those things which no one had previously taught, and which could not be learnt in any quarter by those who were eager on the subject, I have laboured as far as I could (for I have no great opinion of anything which I have done in this line) to explain to our fellow-countrymen. For this knowledge could not be sought for among the Greeks, nor, after the death of our friend Lucius Ælius,(6) among the Latins either. And yet in those old works of ours which we composed in imitation of Menippus,(7) not translating him, sprinkling a little mirth and sportiveness over the whole subject, there are many things mingled which are drawn from the most recondite philosophy, and many points argued according to the rules of strict logic; but I added these lighter matters in order to make the whole more easy for people of moderate learning to comprehend, if they were invited to read those essays by a pleasing style, displayed in panegyrics, and in the very prefaces of my books of antiquities. And this was my object in adopting this style, however I may have succeeded in it.