What speaks against the idea that intense sensual pleasures go beyond the limit of absence of pain? (my ideas: short-livedness, negative consequences of maintaining these pleasures e.g. numbness, hedonic treadmill, costs, ungratefulness, harming friendships and other values ( which are in core Pleasure) ...)
Instead of "short-livedness" and as long as the pleasure didn't cause unwanted/painful consequences, then one would simply feel a sense of gratitude and appreciation to life for having been able to experience that particular short-lived pleasure.
As for anything that feels like it is a "hedonic treadmill"...I would suggest slowing down and putting more attention on the specific experiences and to "open up the senses" to be fully present both in your mind and body.
As for anything that feels like it is a "hedonic treadmill"...I would suggest slowing down and putting more attention on the specific experiences and to "open up the senses" to be fully present both in your mind and body.
To agree and expand: When seeking ever more pleasurable activities, the range of experience gets increasingly narrow. It is common knowledge that with drugs, increased doses are needed to elicit the same sensation; however, the same basic principle applies to all comforts. Eventually, one hops from one previously-pleasurable activity to the next, without deriving much satisfaction from them anymore. Additionally, ordinary chores become increasingly excruciating.
This is why that which one should habituate oneself to are simple pleasures. Only then can '"opening up the senses" to be fully present both in mind and body' really break the hedonic treadmill. That is to say: The hedonic treadmill is broken by widening the range of experiences towards the painful. This is how joys that turned bland eventually regain their brilliance; and by being prudent and putting some limit indulgence, they can keep that brilliance until the day we die.
What speaks against the idea that intense sensual pleasures go beyond the limit of absence of pain?
Speaking in a physiological manner, either a receptor is fully (ant)agonised or it isn't. As such, even on the biochemical level, the absence of pain is the limit of pleasure. (Substance use, particularly using superagonists or otherwise in high doses, can exceed what the body evolved to experience, creating states of bliss unachievable by natural means; however, the result is long-lasting, sometimes permanent anhedonia, as even the most beautiful day pales in comparison to our modern level of chemical engineering…) If you're speaking of one's absolute limit of pleasure, as opposed to what is possible in the moment (which is less), or what is sustainable (which is even less), to be a bit blunt about it: States of intense sensual pleasures paired with the absence of all physical and mental pains, the very moment of climax, say, would be that limit, I suppose. The absolute limit of pleasure is not eating an apple in a tent, because while you do that, you might long for the presence of a loved one and a comfortable bed – however, that might be the limit of pleasure sustainable during a long trek.
Note that pleasure is present only where and while pain is absent. I can laugh at a joke while my knee hurts. My knee can hurt while my skin, bones, muscles and sinews left and right of it feel good.
Pain is not the only path towards pleasure.
I agree with everything you said, except for this; it's just not possible, physiologically. Your nerves will eventually de-sensitise and get used to whatever pleasure they consistently get, unless that is interrupted sufficiently long and often to re-sensitise them, the only way to do that is by pain, and this is true equally of mental and bodily pleasures, because in the end, both are just nerves.
The average life easily contains enough pain to achieve that re-sensitisation. However, there is no pleasure in warmth which has been there, unchanging, for your entire life. Likewise, there is no pleasure in eating cake, if that's all you've ever been eating. And finally, the only sustainable way to solve this is to get out in the cold, have some bread and water – and that can be done reluctantly, miserably, or you can embrace it and make a day of it. Either way, it entails the pain of having no cake and no warmth for a while. Does that mean it is net painful? No, of course not; but being cold is not a pleasure in itself, either.
There is joy in variation because variation itself is a joy (for most people). However, by necessity, there is no variation in being constantly at the absolute limit of pleasure. There is a much lower, sustainable limit of pleasure, where a stronger pleasure is recurrently interrupted by a weaker pleasure; and because everything is relative, including pleasure and pain, that means variation, by necessity, interrupts pleasure with pain. That's just how nerves and neural networks work.
There's no such thing as a permanent high; there's also no such thing as a permanent low. With time, what is perceived as neutral shifts. The same is true for the extremes we can handle, both positive and negative, because what we perceive as endurable shifts, too.
I cannot make my warm, soft, calm corner any better by making it warmer, softer or calmer; it is already perfect. So when it gets boring to my Self (my body seems like it would love to stay there forever), the only thing I can do is to get up and leave it behind – but that's physically painful compared to staying where I was. It is a net positive, because my mind is happy – but my skin and bones are unhappy. If I wouldn't simply embrace that as a part of life and focus on what is to be gained, it would only serve to add mentally misery to the physical pain, and that certainly wouldn't help things.
Anyways, I rest my case. Agree to disagree, I suppose? 
PS: I think "to embrace specific calculated pains" was a bad choice of words for what I mean; "to both accept and dismiss specific calculated pain" might be clearer: It feels painful to go for a hike through the ice (feedback from my body), but that doesn't mean I am in pain while I do it (state of my Self). With other things, I am in pain while I do them (current state of my Self), but I do them anyway because I know it will pay off later (projected future state of my Self and/or my body). What I am aiming at is to not whine about the cold after I made the choice to go out (which will only make me miserable), but to focus on all the rest (which is probably the same as to say: tap into the background pleasure TauPhi mentioned?) or at least focus on the future.
Some of my earliest insights into EP was the cup graphic. Once you've stopped your cup from leaking through psychological work like EP, and deciding you will keep it filled by living joyfully through arranging one's life as to generally avoid psychological pain firstly and physical pain secondly; as well as fortifying the natural restlessness of ego through securing pleasant relationships, you can be untouched by what most of life throws at you and indeed walk among others feeling as happy as Zeus. I interpret the "absence of pain" to just be a sort of lost in translation or out of context way of saying you can have the "baseline" pleasantness by achieving ataraxia/katastematic pleasure. As long as you are not pained by a poorly arranged life and poorly arranged psyche, pleasure and salvation are easily had. That is both my experience of having experienced ataraxia as well as experincing a rather remarkable salvific psychological effect. Not saying it's the only way or the way to interpret it, but it's how I choose to interpret it as my results speak volumes to me at least.
I also feel like I am driving ever onwards with abidding pleasure in the face of all the tumult, war drums and death rattles, even whilst being a Dad to two young children. I may have a day now and then where I need to deeply reflect and at times formulate something grim and dire that could be taken as a Stoic practice, but I believe there is much teeth lost to us that may have been in non-extant works of Epicurean Philosophy. To face dire forecasts one must adopt a sort of gallows humor and "spitting contempt on life and on those who here vainly cling to it" as VS 47 says. For that I reject the notion that a proper Epicurean life must always aim towards an imitation of the Blessed Death of Epicurus, living long and well and tending to more refined business of reciting our will, in order to have said to have lived as an Epicurean. But I will stop there as I digress.
continuous pleasures […] sustained pleasures
What we consider to be painful and pleasurable is relative to our past experiences. Pleasures and pains both wear off with time. As such, no single pleasure can be sustained continuously – and that's not an opinion, that's biology. Now, the fragment uses the plural; that can be interpreted in a number of ways. However:
Whenever one pleasure ends and another pleasure begins – when, say, the pleasure of warmth ends to be replaced by that of a long winter hike – that winter hike will, by necessity, contain the pain of the absence of warmth and the presence of cold; vice versa, the winter hike contains the pleasure of watching bird and breathing fresh air, which were absent inside the warm cabin. In this way, by necessity, every pleasure – if at all, save only that of brief ecstasy – contains some pain.
How that pain is met is just as important as how the pleasure is met; and I chose to accept it as a fact of life, and dismiss it as fast and best I can, focusing my attention elsewhere instead (something I called "embrace" before).
Furthermore, what we consider a good time is relative to our past experiences (and unnatural desires instilled through media and society at large); today's good week is tomorrow's normal week, and also today's bad week is tomorrow's normal week. This is why, in times of abundance, running away from pain will only serve to narrow down the corridor of what is experienced, whereas in times of want, running away from pain will serve to widen the corridor of what is experienced.
Now, one might think: "That's fine, I'll narrow the corridor way up there, where all the pleasures are." However, that is precisely what doesn't work – because, as I said initially, pleasures wear off with time, and so that will be one dull, bland and pale corridor to rot away in. Instead, in times of abundance, the way to go is to seek out discomfort and pains to maintain one's experience of good things as pleasurable.
As for times of want, I suspect the vast majority of us, myself included, doesn't live on a remote trapline in the Yukon, where what is necessary for mere survival entails more than enough discomfort, pain and struggle already; and neither did Epicurus, which is why the Letter To Menoeceus says:
To grow accustomed therefore to simple and not luxurious diet gives us health to the full, and makes one alert for the needful employments of life, and when after long intervals we approach luxuries disposes us better towards them, and fits us to be fearless of fortune.
I don't see the point in whining about the cold and the struggle, when I could just embrace it to get going to begin with, could just accept and dismiss it while I'm at it, and in this manner enable myself to shift my attention and enjoy breathing clear air, watching the birds.
Living in continuous pleasure without a recurring, prior pursuit of that pleasure is harmful, because it invariably leads to a progressive narrowing of the corridor of things which bring pleasure, which is at the very heart of addiction. The only way to keep that corridor wide and open is to do unpleasant things: Chop all the firewood for winter, instead of having it delivered. (There's nothing wrong with, e.g., earning money to then have firewood delivered. That's not instant gratification; there was a struggle for that pleasure, it was just done differently.) Clean your own house, instead of hiring a maid. Save up instead of taking out loans. Take a cold shower. Pleasure without pursuit switches the brain to an endorphin-driven system instead of a dopamine-driven system, and that means it kills one's motivation and drive, resulting in a lifestyle that is a pain in itself but very hard to break out of – because to break out of it one would need motivation and drive. That deadlock only exists, because abundance is not what we evolved to live with; humans thrive in struggles – well-chosen and calculated to yield net pleasure, but still: struggles. We thrive with pleasures which require recurring prior effort to capture them. Avoiding all struggle results in living with a big box of junk food, smartphone in hand. Instant gratification, no drive.
The opposite (dopamine-driven) route is that of purposely seeking out pleasures that are hard to get. In pursuing them, in accepting-but-dismissing the pain involved to get to them, one will at worst make oneself unusually motivated and driven, but that's not such a bad thing, because there are always nice adventures to be had. Those are the people who want to get out, want to go on a hike, a bike ride, build a shed, get things done – and who, in the end, happily enjoy even the simple pleasures nature readily provides, such as fresh food and clear water.
Now, I really want to agree to disagree, and that's why to be fair I'll read replies, but I won't reply in turn, because I don't want to argue this point any further (as I consider it to be a biological fact).
Thanks Julia. I will pursue exploring human Dopamine and Endorphin systems more thoroughly as naming the systems may offer up some science-based insight as to why I had a sudden shift towards mental wellness while not necessarily needing to change much about routine but in the act of letting go of all ambition and ego-defenses. Perhaps I had "switched pleasure systems" and began using different parts of my brain that were not malformed or dysfunctional. All speculation as I do, but striking for me none the less.
I will only comment further by saying that while I disagree with some of the general attitudes aimed at either system, I respect this formulation if it serves you and will refrain from any defense or critique per your request. Sometimes we do need liberal use of periods as we write the story of our lives and our philosophies instead of endless commas and semi-colons.
Dopamine and Endorphin systems
I continue to recommend the book Dopamine Nation for some interesting insights:
