First of all then, said he, I will proceed in the manner which is sanctioned by the founder of this school: I will lay down what that is which is the subject of our inquiry, and what its character is: not that I imagine that you do not know, but in order that my discourse may proceed in a systematic and orderly manner. We are inquiring, then, what is the end,—what is the extreme point of good, which, in the opinion of all philosophers, ought to be such that everythingcan be referred to it, but that it itself can be referred to nothing. This Epicurus places in pleasure, which he argues is the chief good, and that pain is the chief evil; and he proceeds to prove his assertion thus. He says that every animal the moment that it is born seeks for pleasure, and rejoices in it as the chief good; and rejects pain as the chief evil, and wards it off from itself as far as it can; and that it acts in this manner, without having been corrupted by anything, under the promptings of nature herself, who forms this uncorrupt and upright judgment. Therefore, he affirms that there is no need of argument or of discussion as to why pleasure is to be sought for, and pain to be avoided. This he thinks a matter of sense, just as much as that fire is hot, snow white, honey sweet; none of which propositions he thinks require to be confirmed by laboriously sought reasons, but that it is sufficient merely to state them. For that there is a difference between arguments and conclusions arrived at by ratiocination, and ordinary observations and statements:—by the first, secret and obscure principles are explained; by the second, matters which are plain and easy are brought to decision. For since, if you take away sense from a man, there is nothing left to him, it follows of necessity that what is contrary to nature, or what agrees with it, must be left to nature herself to decide. Now what does she perceive, or what does she determine on as her guide to seek or to avoid anything, except pleasure and pain? But there are some of our school who seek to carry out this doctrine with more acuteness, and who will not allow that it is sufficient that it should be decided by sense what is good and what is bad, but who assert that these points can be ascertained by intellect and reason also, and that pleasure is to be sought for on its own account, and that pain also is to be avoided for the same reason.
Therefore, they say that this notion is implanted in our minds naturally and instinctively, as it were; so that we feel that the one is to be sought for, and the other to be avoided. Others, however, (and this is my own opinion too,) assert that, as many reasons are alleged by many philosophers why pleasure ought not to be reckoned among goods, nor pain among evils, we ought not to rely too much on the goodness of our cause, but that we should use arguments, and discussthe point with precision, and argue, by the help of carefully collected reasons, about pleasure and about pain.