I like the observations on justice, and the shift in morality-sphere with the addition of victims. I believe that has been my general reasoning for the anti-anders position. Although, as Solas has suggested, the difference between justice and vengeance is not clear-cut - there is a traditional idea of "Justice" as a double-edged sword, that can be used to justify all manner of good and bad acts. A spirit of justice possessing you is asking for trouble! Yet the balance between freedom and limitations is always a matter for debate, and my guess is this is something Anders (and the position of mages in general) prompts us to think about.
Though I have also been making some alternative (terrible) links recently! With the Tranquility brand on the forehead and madrar's observation of the corresponding part of the brain being responsible for intent, I have been looking into possible reasons for why that part of the brain being "branded" is responsible for being cut from the fade in DA. I won't go into detail because my notes are still all over the place (and I am not a psychologist so I must rely on the word of other students who are) but the closest comparison I have come to are the symptoms of Schizophrenia. Or rather, the elements of a Schizotypal personality belonging to those who have Schizophrenia in their genetic line. So, there is the idea of particular traits belonging to family "blood lines" there (like magic). There is also the familiar concept of magic developing during puberty, which is also when Schizotypal symptoms emerge.
Some still look at Schizophrenia and Psychosis as particular mental states. Others (like I tend to) see a spectrum of characteristics with those conditions as extremities of that spectrum. The personality characteristics attributed to this spectrum are:
> Introversion. Asocial behaviour.
> Deficiency in ability to feel pleasure or stimulation
> Nonconformity. Sometimes "impulsive" nonconformity - unstable in regards to rules and social conventions.
> Thoughts often become derailed, disorganised, tangential.
> Unusual perceptual and otherwise cognitive experiences e.g. hallucinations, magical or superstitious beliefs and interpretation of events
> Passionate interest in "otherworlds" (fantasy, sci-fi etc). Sometimes referred to as "meta-magical tendencies".
The reason I bring this up in regards to circle mages is... firstly, the ethics of guardians responsible for the care of those deemed by society as mentally "abnormal" in some way. In real life it is a constant difficulty of our peers to find the balance between preserving the "natural human rights" of an individual and providing the care required.... and knowing when and how that care involves stepping in and protecting that individual from themselves. That sounds degrading at first, and it is to most with self-awareness or a sense of pride. Autonomy is something many people value in themselves.
However, the above symptoms can also intensify over time, leading to a general degrading of mental state. A mage succumbing to abomination can be seen as an extreme case of Psychosis or Schizophrenia.... where it is argued these cases require full care, observation, and protection. The Tranquil can be seen as someone suffering mild symptoms being given medication to "stabilise" them. From experience I can say the medication's side effects can include cutting you off completely from the ability to express emotion, and to dream... in DA, it is referred by some as "unnatural" - and at first, being unable to cry when it is generally expected you should, is an "unnatural" feeling experience. But, one could argue that once in a state of being unable to express emotion, one recognises the personal gain from no longer being burdened by an unstable mind, and is content being able to function in a way that is desirable to others.
The problem with mages as others have mentioned is the potential for abuse by others. There is always a question of how to include the various degrees of "mentally impaired" under the heading of ethical consideration. There are, however, those who actually do believe that if someone either cannot function as a contributing member of society, or have no or little capability of rational thought and reasoning, their lives have less or no value. There are philosophies and societies out there which do not believe that every life has inherent value, and does not qualify for "natural rights" - or believe in the existence of "natural rights" at all. People with these beliefs feel justified in neglecting the "mentally impaired" from moral consideration... and therefore, can do whatever they want to them while keeping their consciences clean.
There is also the issue of deferring judgement of your own condition to someone who in theory (or *claims* to) has more wisdom about the subject than you. For mages, if they fear their own declining mental state, they can ask to made tranquil. It is akin to making that journey to the doctor and asking for medication which would "stablise" you. Both acts require a certain degree of relinquishing autonomy - admitting firstly that there is a problem, admitting you cannot solve the problem yourself, and admitting you need someone else to take care of your needs in this regard. Admitting that your autonomy is no longer prioritised above your health is an invitation to those who would in future abuse that notion to wrestle you of your sense of "what is right for you". It is ripping open your chest and leaving your heart vulnerable. It is a horrible process, to come to believe that you must trust your general-well being to another person who you are not entirely certain considers your best interests.
But it isn't just those directly responsible for their care we need to question. The greater picture of DA is where and how we could incorporate mages (and tranquils) into general society. We see in the example of Tevinter that not only is it possible for someone with these symptoms to be fully functional in society - these "tangential" symptoms are revered and celebrated. This tells us that attitudes toward magic (and using these comparisons, to mental illness) are cultural attitudes. Seeing mild schizotypal symptoms, such as a fondness for fantasy and sci-fi or noticeable introversion as "abnormal" is something (depending on location) seen as undesirable for a community, for it's implied lack of stability. Yet this is all perception; an opinion cultivated by peers. Tevinter evidences how another culture can embrace the "quirks" of this type of personality.
We see this evidenced in the RL argument between spirituality vs religiosity; when examples are given of historical figures who we, from what we know of them, can conclude probably did suffer with a condition we would class today as a "mental disorder". For example, Martin Luther is said to have been known to wash his hands continually, telling the priests of his original church that his hands never felt clean - driving him to find out why. Today, it would be a safe guess that he suffered with OCD. Interesting that he would go on to have such a profound effect on the direction of religion in history; potentially a result of his "unusual perceptual and cognitive experiences". Would he have been so revered if society had labelled him as they would today?
Labels are key, I think. In DA, it seems when the word "mage" is mentioned, different tangential meanings spring to mind for different people. They might include "dangerous", or "powerful", or in Solas' case "bearer of unique knowledge". But the label of "mage" is inclusive of various concepts which do not allow for the same individualism others who are not mages enjoy. The same goes for someone suffering from a mental condition... somebody says they suffer with anxiety, or depression, or something else, and others have a range of preconceived ideas as to what those conditions entail. Getting to know that person's individual experience regarding that mental condition is not a priority, if it is even considered. It could be one reason explaining why Solas specifically has such a drive for the concept of individualism, as something generally denied (in recent years in Thedas) for mages in particular.
Oh man I am going to stop now because I already wrote much more than I meant to (brainsquirting), but it is such an interesting topic! I have always felt an affinity towards mages and since I have been thinking like this I realise just how personal this affinity is haha.
Anders suffering from a declining mental state really does have my sympathy. However, I still do not believe anything would justify blowing up a church, sorry guys!