A player in our group points out that, at least in some cases, longevity rituals directly affect tissue to preserve the target. He wonders if this slows or stops bodily corruption until the ritual expires.
Interesting thought. It presents the possibility of magus' corpse being mistaken for a saint or a vampire.
Longevity rituals end when there is an aging crisis. I would expect that being dead would qualify, even if they did not die of old age, given the stresses on the body from not breathing, consuming food, etc.
This looks like a fantastic thing to use as a plot hook. It's very reasonable to think of someone losing their sanity experimenting on the longevity ritual and getting that as a side-effect. Or an effect of personal or local Warping. There are a lot of good ways to have this start a plot, even if you don't want this to be the default actions of a longevity ritual upon a body.
The obvious extreme, of course, that if the longevity ritual is still active, then the corpse is still getting warping, which means it may become a vampire; if there already were rumors of Plotticus Hermeticus being a vampire because of his extended age, then you damned well better believe that a vampire-faerie will appear once he's dead.
It makes sense to me that, mechanically, a dead body checks for aging (which is to say, rotting) daily rather than yearly. I don't know that death through a non-aging crisis invalidates the longevity ritual.
I would imagine that there's something metaphysical going on at the difference between "Living body" and "dead body" - as otherwise, the PcCo "destroy corpse (lvl 5)" and "one-shot Insta-kill (lvl 30)" guidelines would be identical.
Probably something akin to "Creo makes something as good as it can be, and a dead body can't be a living body. Thus, a guideline based on the target being a living body won't affect it once it transitions into a dead body." Or "A living body has the ability to heal and repair itself. A corpse does not."
There are similar different guideilnes for plant products vs. living plants, and animal products vs. living animals.
EDIT - although I would suppose you could define a Longetivity ritual as "prevents a body from aging" as opposed to "prevents a LIVING body from aging" - in which case it could affect both. But arguably a dead body rots (ie, falls apart slowly), rather than ages (becomes less effective, but still has the capability of healing itself).
So I suppose it would depend on whether or not you considered a "prevents living thing X from aging" to be an extension or superset or improved guideline of "prevents dead version of X from aging". Which I guess is really just restating the question in guideline form.
Barring an explicit ruling, my intuition tells me that they're (hermetically or Aristotillian-ly) different, so no. I'd say not.
Ah - according to the collated guideline list, "Keep a corpse fresh" is a CrAn lvl 2 ability [Covenents, pg. 50]. It's reasonable to assume that CrCo has a similar guideline. So, it's listed as separate; as such without an explicit statement, I'd say that the guideline for creating a Longetivity potion doesn't include this guideline as well.
That being said, I see no harm in interpreting it that way, so I'd have no problem whatsoever having it be a houserule, or (as others have suggested) a Longevity experimental side-effect.
More than similar, exactly the same. Preserving a corpse from decaying is base CrCo 2 in the corebook.
Thinking about that guideline... what about an enchantment? Maybe some magi just doesn't like the idea of rotting after their deaths, and wear small rings that constantly cast a spell to preserve the touched corpse from decaying (CrCo Base 2, +1 Touch, +2 Sun, +1 Two uses per day, +3 Environmental condition, total level 14). While they are alive the spell fails and/or is resisted by Parma (unless someone kept in at one. What a philanthropist). But once they die the effects kicks in, and future generations of magi can venerate your preserved dead body! (or animate it and make it dance and do obscene gestures).
I can even figure out a Verditius selling this kind of items to mundanes.
And now back to the OP: what if a magus didn't have this (silly) enchantment, but other active CrCo one? Then if the enchantment is constant then it could still affect his corpse, and so preserve it from decaying.
I wonder if peacock feathers or items in the shape of a peacock would get a bonus:
As Augustine and Isidore comment the flesh of the peacock is supposed to barely decay after death.
I think longevity rituals act to slow the effects of aging on the body rather than prevent rot or decay (magi with longevity rituals can still get abscesses or necrotic infections, and I don't believe you are magically prevented from getting tooth decay just because you have a longevity ritual) - then again, the details are left vague enough that your troupe can houserule what it likes.
or better yet, create a corpse, preserve it, animate it, transform your consciousness into a spectral/magical form and then possess said corpse... maybe living ghost where the "haunt" is described as the newly created corpse?
Steering this back toward intent:
Not talking about a magus deliberately preserving themselves. They could do this, no question.
Talking about the unintended side effect of a longevity potion possibly being slowed or halted postmortem decomposition.
If such an effect exists, is it known to magi? Does it have social impact?
I wouldn't expect it to be universal, but it could certainly happen. Honestly I would expect warping to have a greater impact on this than a longevity ritual, with possible exceptions depending on sigils. Of course it could have an effect that isn't so noticeable- like slowing decay for the first 24 hours, or slowing it by 2%...
I never thought of this before but I like the idea.
It calls to mind the legend about the death of Solomon, in which the demons and jinn under his command believe him to be standing in silent contemplation and continue to build his temple until his staff finally disintegrates with decay and his body falls to the ground.