Cicero makes that objection in book two of On Ends: this is from the Reid translation;
QuoteBut Epicurus, I imagine, neither lacks the desire to express himself lucidly and plainly, if he can, nor deals with dark subjects, as do the physical writers, nor with technical matters, like the mathematicians, but speaks on a doctrine which is perspicuous and easy and which has already spread itself abroad. Still you do not declare that we fail to understand what pleasure is, but what he says of it, whence it results not that we fail to under- stand the force of the word in question, but that he speaks after a fashion of his own and gives no heed to ours. If indeed his statement is identical with that of Hieronymus, who pronounces that supreme good consists in a life apart from all annoyance, why does he prefer to talk of pleasure rather than of freedom from pain, as Hieronymus does, who well understands what he is describing? And if he thinks he must add to this the pleasure which depends on agitation (for he thus speaks of this sweet kind of pleasure, as consisting in agitation, and of the other, felt by a man free from pain, as consisting in steadiness) why does he fight? He cannot bring it about that any man who knows him- self, I mean who has thoroughly examined his own constitution and his own senses, should think that freedom from pain is one and the same thing with pleasure. It is as good as doing violence to the senses, Torquatus, to uproot from our minds those notions of words which are ingrained in us. Why, who can fail to see that there are, in the nature of things, these three states, one when we are in pleasure, another when we are in pain, the third, the state in which I am now, and I suppose you too, when we are neither in pain nor in pleasure; thus he who is feasting is in pleasure, while he who is on the rack is in pain. But do you not see that between these extremes lies a great crowd of men who feel neither delight nor sorrow?’ ‘Not at all” said he; ‘and I affirm that all who are without pain are in pleasure and that the fullest possible.’ ‘Therefore he who, not thirsty himself, mixes mead for another, and he who, being thirsty, drinks the mead, are in just the same state of pleasure?’
And in the first book, the Epicurean Torquatus touches on the problem of "Chrysippus' Hand", which deals with the same question;
QuoteEpicurus thinks that the highest degree of pleasure is defined by the removal of all pain, so that pleasure may afterwards exhibit diversities and differences but is incapable of increase or extension. But actually at Athens, as my father used to tell me, when he wittily and humorously ridiculed the Stoics, there is in the Ceramicus a statue of Chrysippus, sitting with his hand extended, which hand indicates that he was fond of the following little argument: Does your hand, being in its present condition, feel the lack af anything at all? Certainly of nothing. But if pleasure were the supreme good, it would feel a lack. I agree. Pleasure then is not the supreme good. - My father used to say that even a statue would not talk in that way, if it had power of speech. The inference is shrewd enough as against the Cyrenaics, but does not touch Epicurus. For if the only pleasure were that which, as it were, tickles the senses, if I may say so, and attended by sweetness overflows them and insinuates itself into them, neither the hand nor any other member would be able to rest satisfied with the absence of pain apart from a joyous activity of pleasure. But if it is the highest pleasure, as Epicurus believes, to be in no pain, then the first admission, that the hand in its then existing condition felt no lack, was properly made to you, Chrysippus, but the second improperly, I mean that it would have felt a lack had pleasure been the supreme good. It would certainly feel no lack, and on this ground, that anything which is cut off from the state of pain is in the state of pleasure.
XII. Again, the truth that pleasure is the supreme good can be most easily apprehended from the following consideration. Let us imagine an individual in the enjoyment of pleasures great, numerous and constant, both mental and bodily, with no pain to thwart or threaten them; I ask what circumstances can we describe as more excellent than these or more desirable? A man whose circumstances are such must needs possess, as well as other things, a robust mind subject to no fear of death or pain, because death is apart from sensation, and pain when lasting is usually slight, when oppressive is of short duration, so that its temporariness reconciles us to its intensity, and its slightness to its continuance. When in addition we suppose that such a man is in no awe of the influence of the gods, and does not allow his past pleasures to slip away, but takes delight in constantly recalling them, what circumstance is it possible to add to these, to make his condition better? Imagine on the other hand a man worn by the greatest mental and bodily pains which can befall a human being, with no hope before him that his lot will ever be lighter, and moreover destitute of pleasure either actual or probable; what more pitiable object can be mentioned or imagined? But if a life replete with pains is above all things to be shunned, then assuredly the supreme evil is life accompanied by pain; and from this view it is a consistent inference that the climax of things good is life accompanied by pleasure.
We discussed the passage from book two in episode 201 of Lucretius Today, which I remember being one of our better efforts...