Sense pleasure comes from gratified physical appetites.
There is a different order of pleasure -- intellectual, spiritual or aesthetic -- that comes from gratified higher appetites. He says these are closely related to joy but not quite the same thing, because joy can exist without even these and in fact MUST exist somewhat independently of these in order to be true, not contingent happiness.
So, to contrast sense pleasure with joy:
Sense pleasures are localized; they affect a particular area of the body (like chocolate gratifies the taste buds). Joy is generalized. It is compatible with physical and sometimes even emotional suffering (I know from experience, from feeling joy even while I was going through lots of discomfort and heartache with Aidan in his worse moments in the hospital. Though I do remember the joy having something of a sensory focal point in a latte I got with my husband at Border's one bleak time, so maybe it's possible for taste in the right circumstances to be associated with something more generalized?).
Pleasures need a specific material, sensory stimulus. Joy arises from intellectually appreciated stimuli or from immaterial reality itself. Joy may be triggered by something perceived through the senses, like music or natural beauty, but the joy does not fade with the stimulus fading -- it is retained in the mind or spirit.
Pleasures are limited in duration and can easily be over-extended. CS Lewis talks about this in Screwtape Letters, saying that sense pleasures seem to come with an impulse to be overdone, which results in bad effects -- disgust, diminishing returns, over-indulgence, even illness. Whereas joy is durable and the highest joy is illimitable, bigger than we are ourselves, and does not lead to bodily illness or degradation.
Pleasures can be taken away. Aristotle points this out -- natural goods, even the higher ones like health and good reputation, can be wrenched away at a moment's notice. Joy can't be wrested from us against our will.
Sense pleasures ARE good -- it is our nature, not theirs in themselves, to use them in a distorted way. It's good to remember when reading about a saint who scorns something obviously good in itself, like, say, whiskey or mocha cheesecake, that the saint is not targeting the thing itself but his own reaction to it, which is hindering his desire for true excellence. Proper asceticism is strictly speaking "athletic training" -- something that helps us bring our bodies under the control of our will and reason. Just as slacking would lessen one's athletic potential, so focus on sensory appetites diminish our human potential to go beyond material things. Sense pleasures, thus, have a tendency in us humans to fix us in temporality -- to make us concentrate on the gratification. Whereas joy tends to fix us more towards eternity and timelessness -- to put it in secular psychological terms it relates to what Mihaly Csikszentmihalyi calls "flow".
He writes a lot more about joy and the Christian life but this is probably enough for now. I do think it's important to remember, however, that voluntary poverty has intrinsic joy simply because humans, by their nature, want happiness to be:
- Securely in our possession
It strikes me, though he does not say it, that pleasure has a wholly subjective aspect while joy, though subjectively experienced, has an objective quality. It is to do with something that would be good even if I didn't happen to exist to experience it. I realized this very strongly as a teenager, living in a subjectively oriented world and craving something outside of that, something that mattered of itself, not just through my incidental sensory connection with it.
Plus, and this part I am thinking out myself based on what he's said in other parts of the book, there is an element of loyalty and affection in joy that does not exist in sense pleasure. When you think of it, most "joys" -- response to beauty or intellectual realization or affection for a dear one -- are connected to a recognition of relationship, of connection. Whereas sense pleasure is almost inevitably self-centered (with some qualifications, like when we are enjoying a celebration or feast and having delightful food in that context, etc). Or at least when it's disordered, it's invariably self-centered, I think. Humans are ordered towards true communion, which is why both romantic love and sociability are so important to them, and can become distorted if they are over-prioritized.
Our priest today said something to the effect that love and compassion only exist as they are shared. This is one reason why God has to be a Trinity, you see. But it's also the reason why peoples' sincerity of love is measured by sharing. Not only sharing our worldly goods, but choosing to share in something Our Lord and Redeemer freely chose -- to give up wealth and self-will, to choose poverty and obedience not for themselves but for the sake of others. When we're married to someone or born into their family we share their fortunes freely -- "for better or for worse, in sickness and in health". The limitations don't measure up against our love. It is a natural truth and at the same time a "type" of a supernatural truth. When we truly care about others we feel tied to their fortunes in some way. It is a pleasure, or rather a joy, really, to participate in Our Lord's free poverty. That is something to be always kept in mind when thinking of poverty. It's a negative in a way but one of those negatives that cast the positive into clearcut relief.