Essential Nature

The Law of Essential Nature states:

[i]"...While Hermetic magic can completely change how a thing appears, it cannot affect what the thing is.

...All human beings are essentially human... men are essentially male, and women essentially female, and other people have other factors in their essential nature. For example, some people are essentially blind...[/i]" (p. 79-80)

However, under the general Corpus guidelines, it says "Corpus spells with human or human-like bodies and anything that involves those bodies" (p. 129), and under Mentem it addresses "intellegent minds" (p 148).

So...If a human is turned into a pig by magic (hermetic, faerie or other), is it true that no Animal spell would then effect them? If a loyal dog were given human form (The Beast Remade, MuAn 25), could they not be healed with Corpus?

If an animal were elevated to "human" consciousness, would Mentem spells then effect them?

Altho' a spell does not detect a Bjornaer in beast form as human or changed, would a Mentem spell effect them, since they are, essentially, intelligent (and it is essentially a "human" mind)?

Does Animal effect a Familiar's essentially "animal" mind, or, because of their potential intelligence are they, once bound as an intelligent familiar, "essentially" more Mentem?

If it's true that there are those born to Rule, born to Pray, and born to Toil, then does "Aura of Authority" then go against this rule, just as one cannot hide The Gift, or a holiness? (remember the Medieval Paradigm re "blue blood" etc)

Would changing the color of a person's skin go against Essential Nature? (remember the Medieval Paradigm, when the people of any foreign country were not seen as "essentially" the same as locals.)

If a person had an unexpectedly strong innate emotion as part of their Essential Nature, would a Muto Mentem spell such as Calm the Motion of the Heart of "Instant" duration then instantly fail if targeted against that, since it did not maintain that change?

If a person lost a hand, a mage could replace it magically. But if born without a hand, what would the options be? (Or born Blind, re a different current thread).

If the hand of the person born without a hand were magically replaced, would that replacement be effected by Corpus, or Vim?
I know how I would interpret most of these, but I was wondering if the rules can clarify the matter.

Well, first of all I think an important reason for this Limit is the fact that is explains, in setting terms, a range of rules that are needed to keep the game in balance. If it wasn't there either alternatives would have to be invented, or we would have to live with rules that were not in sync with the setting - which is luckily a rather rare sight in Ars!

What is this Limt then? For one thing it is the one that sets a cap on the duration of a majority of magical effects (duration Year with Rituals). As it is the only magical effects that can be made permanet are 3 kinds of magic: Momentary Creo rituals, Momentary spells that through their momentary medium effects a change in something else, certain Rego effects. All other kinds of magic is limited in duration mainly due to one thing: The Limit of Essential Nature.

Moreso it is also this Limits that keeps all things in place such as Charateristics and Virtues/Flaws would otherwise by like clay. An interesting notion but at the same time utterly destructive of playing and advancing characters.

How to explain this in insetting terms? The "Hermetic magic can completely change how a thing appears, it cannot affect what the thing is" which might come of as quite confusing might best be explained by a little input from Aristotle. Aristotle's aim was to solve the gap between the form and particular objects. The first being the idea, universal and immutable, of something and the second being the objects we sense - see, hear, touch, taste and smell - in the real world. He wanted a filter of sorts in between to explain the myriad and endless number of particular objects. You might say that the Essential Nature is something very close to the form or idea of things - though not entirely since in it's purest form the form would simply just be 'man'.

In this light the Final Cause is unalterable by magic and this is what is closest to the Essential Nature. That which remains no matter how we affect the object with magic. A magus using magic to some effect becomes the an object's Effecient Cause and instead of tools he uses his magic to (re-)form or change the Formal Cause of the object, that which is sensesible to the world (e.g. sculpting a statue). And magic being supernatural he might even change the Material Cause in the process (e.g. changing a horse's flesh to bronze). The Final Cause; the 'universal' idea, or form, of the horse muto'ed into a bronze statue however stay immutable by the magus.

Thus hermetic magic can completely change an object; and yet it remains unchanged :exclamation:

It is worth an honest attempt.

I think that most of these questions can be enlightened by HoH:MC p. 22. It destinguishes between a change due to a) Heartbeast (Bjornaer only), or b) due to an inherent supernatural power, or c) due to some kind of power with a duration (as a spell for example).

In the case of a) the transformation is utterly on complete (you might say that Bjornaer in all regards have a sort of twin Essential Nature of both man and beast) and he can only be affected with Animal spells in as heartbeast and only by Corpus and Mentem when in human shape

In the case of b) the inherent power, the target could still be affected by Corpus and Mentem (besides Animal spells) when in beast shape as he is still essential human (although some lycanthropes loose their mind during their time as beasts and as such cannot be targeted with Mentem). As the power is only active at the time of the change this shapechanging cannot be dispelled by Vim magics.

And finally the spell version c). This one can still be targeted with Corpus and Mentem (besides Animal spells), but since the change is a continuing spell the target can also be affected by Vim spells (including Intellego) and he is resisted by MR.

I would reckon that the opposite of all the above holds true if it is vice versa - that a beast is turned into a human. With one exception: That the beast cannot get a human mind from a simple MuAn(Co) shapechanging spell and thus Mentem has no hold over it. I somewhat recall having read some examples of this, but it might have been 4th edition (I know the issue is raised in the Triamore sourcebook). It could be interesting to hear some more thoughts on this!

Oh, already gave my two pennies above. I could add that if, only if, you added a CrMe to the shapechanging spell, then you might argue the case, otherwise I would definately say no.

Already been there.

Well. A good question. Since familiars are creatures with Might I do not think that the usual rules apply to them. First of all I would look to what Form their Might is linked to? Is it Animal or maybe even Mentem? Secondly I would look to Charateristics; If Cunning I'd say Animal, if Intelligence I'd say Mentem. In any accord I'd say that this an important question to settle during the creation process of the familiar as to not confuse later events.

I'm less inclined to buy this. The Limit of which we speak doesn't make things outright impossible, it only deems that certain effects have a 'lifespan' and then the magic will disappear to make the target revert to its natural essence. So anyone can be influenced by this spell in any regard (as long as they 'qualify' for as a Mentem target!). Some spells, such as when using ReMe in particular might persist after the end of the spells duration, and then you might argue how this might influence the eventual continuation of the effect. But in those instances, Mentem being elusive, I would look to the targets personality anyway. If using a Mentem spell that grants some kind of roll to resist the effect you might also let this notion add or subtract from the roll.

Again - this Limits really seldom limits what you can do - it only explains why the effects arent permanent. So yes you could change the skin, but it would return to normal after the end of duration.

I would say that if this is represented by a Virtue or Flaw (Essential), then a Momentary spell would only last for a moment (though it might take the character a couple of minutes or seconds after that to get 'worked' all up again depending on the situation. But the spell would not fail as such, it just wouldn't do any lasting difference.

If not a Flaw - no problem - go for it. Although the Limit of Creation would need you to use vis and ritual to make it permanent and unmagical. If a Flaw (Essential)...? That's worse. I would not allow it. Remember that healing is not just a change of someone - it actually draws on the realm of ideas to perfect a thing closer to its 'Final Cause' - and thus a Flaw being Essential in nature the spell would even reckognise that something is amiss or outright missing. It would follow that a Creo spell cant do it at all. Other solution would however not interfere with the Essential nature; make a magical device that acts as your hand answering your mental commands. Tools and devices not part of your Nature can still be quite usefull.

It depends. As noted above it can only be replaced if it isn't a flaw. If the hand is replaced permenantly, with a Momentary CrCo Ritual, then the hand is in all regards mundane -> meaning that it can be affected by Corpus only. If the hand is only healed temporarily, for a month for example, then it is magical (a quick tell-tale sign is whether the spell has a duration) and can be affected with Vim, but by Corpus aswell (granted that the hand is made of Corpus and not some other fancy material).

great answer

Unfortunately, Furion has gotten confused, mainly because his source used a confusing example and is largely wrong:

First, note:

Note that the form is in the object.

I can't begin to express how error-riddled this is. First, note that here, the form is not in the object, it's in the mind of the sculptor. That isn't quite right. The form of the statue is its shape, out in the world. The form pre-existed, as an idea, in the mind of the sculptor; that's one of the neat things about forms: they can exist in different places and times, both in the world and in the mind. But, insofar as it's the form of the statue, the form is out where the statue is.

Second, consider the bronze statue. The example skips between the material cause of the statue (the bronze) and the efficient cause of the statue (the sculptor) and the final cause of the making of the statue. The final cause of the statue is presumably to honor its subject, or some such. The final cause of the making of the statue might be something completely different and, in any event, involves the existence of the completed statue. (Since the statue isn't its own reason for being, it isn't its own final cause, but it can be the final cause of its own creation.)

Third, it is patently false that the formal and final causes are identical. Form is structure; final cause is function. It's true that something's structure is designed around its function, but that doesn't make the two the same thing. My car is designed to take me places, but that doesn't turn my car into a vacation.

Further, note that the Internet Encyclopedia says both that the final cause is more important than the other causes, and also that is is the formal cause, and that it can be subsumed within the efficient cause. Obviously these claims are contradictory: the efficient cause (which means, according to the Internet Encyclopedia, all the causes) can't be less important than the final cause which is a part of itself. Finally, the remark about importance fails to tell us what kind of importance the final cause has more of than the other causes. Each kind of cause is more important, for some purpose, than the others; that's why they all get to be causes. Material and efficient causes are more important for the purposes of (Aristotelian) physics; formal and final causes are more important for (Aristotelian) biology and ethics.

You can more or less read 'form' and 'essence' to be synonyms; indeed, different translations of Aristotle will translate a certain Greek word differently, as either 'form' or 'essence.' If we want to read 'essential nature' into Aristotle, we have to equate it with his formal cause. However, that would be a mistake. For consider that, according to the rules, my height is part of my essential nature, just as is my rationality: neither one of them can be changed for more than a year. But of course my form is rational animality; my height is a mere accidental property, something that I happen to have but needn't have had and could lose while remaining essentially the same, but if I lose my rationality, then I stop being the kind of thing that I am. Height and rationality are equally essential according to the rules, but according to Aristotle, one of them is more essential than the other; thus the rules don't line up with Aristotle on what's essential.

Furion's remark that the limit of essential nature is a rules trick designed to make the game playable is much more on the mark. As with parma, essential nature is whatever it needs to be for the game to work. It relates very badly to anything in Aristotle.

Bryan many thanks for an extensive and very clarifying reply!

I have to admit that I had some puzzling pauses reading the extract of Aristotle I used in this context. I am no expert in Classical Philsophy but it somewhat conflicted with what I recalled, or thought to, recall of aristotlean metaphysics.

I did also have access to a primary ressource, so I can only blame laziness and being tired for having cut a corner and used the Encyclopedia, but it would certainly have done me a greater service to have used his own words.

Though it pains me, as I like to dig up insetting rationalisations to rule issues, your make a goodf arguments against the use of aristotlean metaphysics in this regard. As I sidenote I might add that I also considered using Aquinas' generel metaphysics, though they also draw on the four causes of Aristotle, but maybe with a focus on Act and Potency. Any thoughts on that?

So a person who is essentially blind (having taken the flaw at creation) may not be given sight with CrCo, as Creo would only be able to bring him closer to his essentially blind self, but perhaps could be given sight through MuCo?
It seems that if MuCo can change someone into a bird (with Animal Reqs) which has the ability to fly, and the ability to fly is not part of the essential nature of man, then to give an essentially blind person sight through Muto Corpus (no reqs) would be appropriate as the spell is giving him something he does not essentially have. The effect would simply not be permanent, as a Muto effect has a non-permanent duration. Does this sound reasonable?
Or perhaps sight could be gained with MuIm (or would InIm, target touch be better?) to change the visual species into touch species so that someone could "see" with his hands.
Of course, such a person would be dealing with the warping of a constant magical effect if he had this effect in a constant item and used it all the time.

Well struggling with this issue myself, since I am also toying with a blind magus.

It is quite tricky, but I think it is a question completely up to your own preferences, to interpretation and house rules.

First you have to consider what the Essential Nature of blindness is. This might be differentiated from individual to individual, but out of rule streamlining it might be wise to make a universal ruling on flaws such as this. Back to the Nature of blindness - you might be blind simply because your eyes are missing or damaged (a violent past springes to mind) or be an inate inability to see, recalling that people with eyes can be blind nonetheless. If it is the lack of eyes causing blindness, then you might argue that giving the person eyes with a muto spell might give him sight. If his eyes are fine and not missing, then you might argue that he cannot be helped to see with muto.

The above might sound logical but I think I would be cautious of making such a division - it would divide a Flaw into alpha- and a beta-flaw.

The rules for changing shape specified in HoH:MC makes a point out of remarking how wounds follow you when you change shape. Other spells (MuAn in the RAW on changing animals into humans) stress how the indidvidual is still discernible. You argument does however ring true, but this is a question of game balance, and my gut feeling is to disallow it (even if it might pain my own blind character).

I have been contemplating the Magical Sense spells as well. You have to remember that the magic only 'infuses' the target sense with supernatural sensitivity, but the sense is still basically the same sense, and limited in the same way said sense is limited. In this example the sense of touch can only sense things we.. well.. touch! So he can only sense the things he touch, he cannot sense the door across the room or the culprit sneaking up on him from behind. With this magical sense he might however sense things not nermally sensed by touch (such as colour, whether it is vis, whether it is a given Form etc).

Finally you also have to decide on InIm spells. These can be used to scry from afar. The big question is now whether a blind magus can use a "sense at a distance" if he actually does not have that sense himself? If so he could simply just make a range of spells giving him sight at his current location! Again I would personally dislike it.

Ind the end you have to ask yourself, as do I being in the same shoes as you, why make a Blind character if you have every intention to bypass this completely with more or less semi-permanent magic solutions?

Very welcome.


  1. Aquinas is slightly after the canon game date, so it could well be that Mythic Aquinas is totally relevant.
  2. I think that 'potency' is just 'potential,' and 'act' is just 'actuality.' When you were a kid, you had the potency to grow up; now you have, so your adulthood is act. Aristotle's material cause held potential, and formal cause was what something actually was.
  3. Otherwise, sorry, not really. My history of philosophy basically skips from Aristotle to Descartes with just a couple of highlights in between.

i agree, I am not trying to bypass the blindness, I am mostly trying to figure out how limiting blindness would be for a mage. I think the character should remain blind. Perhaps being able to get a (for lack of a better word) visual image of something by touch

would be a good way to let him read without having an assistant dictate to him. He could simply 'feel' where the page is black and where it is white.

He could also do the "I'm blind, let me fondle and memorize your face" trick really well. :smiley: BTW, I have known a few blind people, none of them ever fondled my face. I guess they never saw all the movies where the blind protaganist did that to everyone. Oh, right. :blush:

Maybe I just don't like the idea of a magus, even a blind one, being heavily dependant on others. I expect being blind to be a pain and severely, but not totally, limiting. For example, I think 'crippled' is also a major flaw, but the mobility restrictions on it can be overcome for the most part with a flight spell. Now that spell can be dispelled, and the magus may have to deal with warping, and he had to spend spell levels simply to be able to move around, something everyone else does easily. So i figure 'blind' should be analogous in its restrictions. It also gets rid of the conversation of "Well, if we are these neato magi, why don't we just do this?" answered by "because of game balance". I would rather the question be answered by "He was born blind and since this limitation is part of his essential nature, it cannot be changed, but we can mitigate a lot of the terrible effects by doing A,B,C, and D, but it takes a lot of time and effort to do so." I think magic, by definition, allows one to overcome essential limitations, but there is a price to pay.

I expect him to be unable to:
Recognize or appreciate anything at a distance, except by sound.
Cast 'eye' range spells.

Look people in the eye. I am not being funny, this would be a real social handicap.

Target spells very well.

Move about freely without casting 'Eyes of the Bat'. Even with this, you can't tell friend from foe. Or read a warning painted on a wall. Or figure out whether the bridge looks rotted or not. Or figure out whether there is steam coming out of the tea pot to avoid getting burned.

Read without magical assistance.

Use laboratory equiptment without personalization. I can imagine his lab assistats and apprentices having a heck of a time, since nothing is labeled.

Use visual CrIm.
Probably have trouble writing books (His handwriting is terrible).

On the up side:
Visual illusions are ignored. Which is good unless your sodalus is trying to send you an image of where he is trapped by the evil fairie lord.

Maybe this should be in the Blind Magus thread.

I don't see any contridiction between a magus with the "blind" flaw not being able to muto eyes and a magus born without wings being able to fly. At least not in a "rubber meets the road" game sense.

The Blind flaw indicates the blindness is part of his essential nature, just as a crippled mage changed into a shark would not be able to swim well.

However, you have no flaw that says you cannot fly (though such a flaw could exist), you mearly don't have the equipment normally.

These contradictions are exactly the reasons that this is house rule material.

My gut feeling as mentioned is against allowing it. If you talk of the equipment to see. Then your focus is on the ocular perception alone, the eyeball (the organ of vision that detects light), but what if the blindness isn't physical in that sense? Many people have eyes, yet cannot see, and thus it follow that creating the 'equipment' might not alone grant sight. Using this approach it is much easier to defend (out of game balance) that MuCo cannot be used to grant sight.

When it comes down to it ,
A Flaw is not worth the points if there is an easy way around it.

Visual Imagery can be implanted via Mentem Magics.
There is a spell that allows speech into writing.
Another that allows a mental diagram to be placed on parchment.
The easiest fix so far is to have a reader/companion.
Radar-type senses allow a Blind magus to navigate.
Touch based reading of text is possible.

If learning is just as easy for a blind magus as a sighted one , due to a Muto fix ,
then blindness is not a flaw for a Hermetic Magus.

Oh, I agree that it's difficult to come up with an in-game justification, I'm just saying within the rules system, it's well taken care of. If you have the flaw you cannot change it with magic.

True. But on the other hand most flaws have a way around them, or at least some dictates to how to manage it. But it takes time and energy, and most of all it is what makes each character unique.

In other words on the bottom line I am not so concerned about the working around flaws or how easy it's done - what concerns me is whether a flaw is taking to add to the fleshing out of a character or just to free up some points in a way that has no bearing on the character or his past.

Many take Flaws that limit an Art, that they would never want or invest xp in anyway. Or to have enemies at the other end of the world. Ot take an ability block with something you would never need or want. If there is no story there, then that to me is much more problematic than having a Blind magus speding time on inventing spells to handle just some of the challenges involved in being blind.

There's another point to consider here.

Most of what's been said above suggests that magic cannot even temporarily go against someone's Essential Nature. That's not what the RAW says, though - it says that a change that goes against someone's/something's Essential Nature cannot have a permanent effect.

Otherwise, a spell that would change a person into a pig (Curse of Circe) would fail, because the target's Essential Nature is that of a person, not an animal.

So, in the case of a magus with the Blind flaw, it's theoretically possible that a Creo Corpus spell (not even requiring a ritual) could temporarily give him sight. Of course, as a SG, I'd not make things that easy - after all, the magus has spent most or all of his life without sight, so he'd likely need some time to get used to it. The possibility is there, but it might require too much effort (and possibly Warping) to make it worth the trouble, and can't be made permanent.

I agree.

But the rub is the balance between Flaws and the endless possibilities of magic. You yourself give some suggestions how to even them out by making the magic solution less easy on the PC.

Another might be to focus on the character generation and the choosing of the Flaws, rather as doing as we've done here to focus on the magic. When the character is being made we might discuss other 'caps' on using magic to solve flaws. As a part of character generation one might find other reasons for the PC not wanting to solve this thing with magic or other explanaitions why said flaw is hard to solve with magic. The blind magus I'm toying with will have some clear reasons for not wanting to restore his sight with magic, even temporarily.

if what you want is a character who can (in practice) see, move freely, and read, but must work hard, and is dependent on spells and items to do so - then they are not inflicted with a Major Flaw (Blind), but you might allow them a Minor Flaw (Blinded, sees with magic).

It's munchkin on the part of the player to demand a Major Flaw (3 points) if they plan to work round it and ignore it.
It is clear from the RAW that Major Flaws are meant to crop up in most stories and to drive entire stories. A magus who starts their career with magical replacement sight isn't actually driving the story with this, compared to one who is unable to see at all and has to start to work to overcome the Flaw.

I agree. Which is way a further down the thread suggested to address the issue during character generation, instead of postponing it to later, and that the charater generation should be used to make choices on why and how the flaw wont be, or be chosen to be, solved with magic, or simply to not take the flaw.

Would the blinded character have the abilities at creation to solve his flaw with magic? Are you starting with a fresh apprentice that can do no magic?
If either was the case I wouldn't see a problem with taking the blind flaw and then spending several seasons/years working to develop the skills to overcome it. In my mind there is no reason a flaw has to remain forever they should always have a way to be overcome as the character progresses (mostlikely gaining new flaws to replace the old)

the usual problem with blind just-Gauntleted magi is that if blind as Apprentices they have so much problem reading that either the parens cures them or puts them out of their misery...