But some people say that there is a sort of agreement entered into by wise men not to love their friends less than themselves; which we both imagine to be possible, and indeed see to be often the case; and it is evident that nothing can be found having any influence on living agreeably, which is better suited to it than such a union. From all which considerations it may be inferred, not only that the principle of friendship is not hindered by our placing the chief good in pleasure, but that without such a principle it is quite impossible that any friendship should be established.
XXI. Wherefore, if the things which I have been saying are clearer and plainer than the sun itself; if all that I have said is derived from the fountain of nature; if the whole of my discourse forces assent to itself by its accordance with the senses, that is to say, with the most incorruptible and honest of all witnesses; if infant children, and even brute beasts, declare almost in words, under the teaching and guidance of nature, that nothing is prosperous but pleasure, nothing hateful but pain--a matter as to which their decision is neither erroneous nor corrupt--ought we not to feel the greatest gratitude to that man who, having heard this voice of nature, as I may call it, has embraced it with such firmness and steadiness, that he has led all sensible men into the path of a peaceful, tranquil, and happy life? And as for his appearing to you to be a man of but little learning, the reason of that is, that he thought no learning deserving of the name except such as assisted in the attainment of a happy life. Was he a man to waste his time in reading poets, as Triarius and I do at your instigation? men in whose works there is no solid utility, but only a childish sort of amusement; or to devote himself, like Plato, to music, geometry, arithmetic, and astronomy? studies which, starting from erroneous principles, cannot possibly be true; and which, if they were true, would constitute nothing to our living more agreeably, that is to say, better. Should he, then, pursue such occupations as those, and abandon the task of laying down principles of living, laborious, but, at the same time, useful as they are?