Some twenty years ago a vegetarian couple and their two young daughters were friends of mine. Even as children, the girls wanted to become veganists, but their father and mother believed they should wait at least until their eighteenth birthday. The parents were not so much concerned about possible health risks, but they considered veganism 'extreme'. They were of the opinion that dairy products don't require the killing of a chicken or cow and you can buy leather for which animals don't have to be killed especially. Regrettably they are certainly not the only vegetarians who believe veganism to be extreme. This is probably even more true for animal protectionists who do not lead a vegetarian lifestyle, and certainly for people who are hardly concerned with such matters as animal ethics or animal welfare. In the eyes of many, veganism is a utopian, unfeasible choice. Not eating meat and fish is often considered sufficiently noble and engaged. Renouncing the use of even more animal products can hardly be considered 'human' from this point of view. It is as if people want to escape their humanity or consider themselves better people than regular vegetarians.
What exactly are we talking about when we speak of an extreme way of living? The word 'extreme' has an almost invariably negative connotation. It is derived from the Latin, where it is the superlative of the adjective 'exterus'(meaning 'external', 'outside of'). From an etymological point of view, the original meaning is 'outermost',' utmost' or 'last' and adverbs such as 'extremely' and 'extremamente' (Spanish, Portuguese) still bear this neutral meaning. The word 'extremism' matches the negative connotation of 'extreme'. Within the philosophical spectrum, an extremist group is always removed the furthest from the moderate center. It will try to enforce its ideology to the utmost. Extremists in the political sense of the word might use violence and bloodshed in their pursuit of a utopia or -in the case of anarchistic extremists- bringing down every form of constitution.
Somewhat similar expressions are 'radical' and 'fundamentalist'. Both terms refer to the groundwork or basis of something ( 'radical' is derived from the Latin word 'radix' which means 'root'). In the case of radicalism, however, the main issue is the pursuit of an ideal while fundamentalism usually means observing some holy book to the letter. The term 'radical' usually evokes fewer negative associations than the words 'extreme' and 'fundamentalist'. Under these circumstances veganists won't easily be accused of fundamentalism, because they are usually to independent to base their entire lives on a literal interpretation of religious writings.
The proper midpoint
Many philosophical traditions show an aversion to extreme positions. They strive to find the middle path between two extremes. Aristotle, for example, stated that people should strive for courage as a path between cowardice and overconfidence. Confucius as well supported a doctrine of the right middle path, according to which one should avoid excesses as much as possible in favor of inner balance and harmony. Siddhartha Gautama the Buddha developed a modest path of life midway between hedonism and undue ascetism. Generally speaking, Buddhists consider their ideology as a faith between philosophical extremes, for example between nihilism and naive realism.
Buddhists are (at least in my understanding) in spite of their compassion for all creatures that suffer, usually no vegetarians in daily life because that would turn out extreme. The killing of animals is not allowed, to be sure, but the eating of animals that have not been slaughtered as food for the Buddhists themselves is permitted (at least for certain schools within Buddhism, online addition).
Extremists are, within this perspective, focused on an extreme position instead of a balanced midpoint. This is why they deal in an unbalanced and immoderate way with their own needs and those of their social environment. They are out of balance and this can only cause misery for themselves and others.
Too much of a good thing
The Dutch version of Wikipedia acknowledges that the expression 'extremist' has a subjective connotation. This is connected directly to the personal ideals, norms and values of the person using the word. What one person considers extreme, is to another merely morally sound or even self-evident. People who adhere to 'an extremely left-winged' ideology don't consider this a problem.
The general opinion is that an ethical principal should not be enforced to the extent that it is harmful to others. It is, for example, good to be friendly to neighbors you don't personally know, but it goes too far to just give them the keys to your house. He that makes himself a sheep shall be eaten by the wolf. In the same way it is good to teach children that they should be willing to do something for their fellow men, but that doesn't mean they should continually give their toys to other children. A morally balanced life also means that you take into account the rights and interests of all involved, including yourself. Merely taking into account the interests of one party is an injustice to the other party. In this case there is an excess of respect for one of the parties involved accompanied by a lack of respect for the others.
I suspect that virtually nobody would want to be an extremist if this means that in fact you are unbalanced. It is true that there are subcultures where people, in a destructive way, mainly turn against a certain status quo without providing an alternative. But most of the extremists, on the contrary, have far-reaching ideals. They do not consider themselves to be extreme, merely radical, specifically meaning 'being consistent in the observation of their principles'.
Why are some radical idealists portrayed as extremists? According to me this has everything to do with the value one attributes to a certain principle and the way this value is contrasted against other values. To proponents of universal human rights, for example, every terrorist is an extremist. However important the ideals are to the terrorist himself, they do not justify the sacrifice of innocents. Terrorist actions aimed at improving the lot of animals should, within this framework, also be deemed extremist. Unless one wants to dehumanize or demonize people who abuse animals to such a degree that they automatically lose their human rights. Or unless the fight for animal rights is, in fact, considered some sort of righteous war in which it is allowed to sacrifice hostile people for the life of innocent animals. Such a way of thought is a problem when you consider that animal rights derive from human rights and that there is no prospect of a speedy victory by using violence. Worse still, a violent battle might cause the introduction of animal rights to last even longer. In this case there is a strong parallel with for example the suicide missions of Palestinian, Kurdish and Islamic terrorists. Their apparent contempt for human rights causes the outside world to lose most of their sympathy for their ideals as well.
Anyway, the extreme aspects of veganism have nothing whatsoever to do with sacrificing the life of our fellow men to that of animals. At the most it concerns cutting back on forms of animal use to which people are attached. This does not necessarily mean a diminishing of quality of life, since vegans usually gain a cuisine they didn't know before. Values such as 'enjoying good food' or 'wearing beautiful clothes' are fully compatible with a vegan lifestyle.
A vegan lifestyle is, moreover, a voluntary choice that is not imposed on others. Other people at the most are 'inconvenienced' by it the way they can be inconvenienced when someone has to follow a diet for medical reasons. This is another respect in which veganism can't be called extreme.
Veganism does not involve the sacrifice of individuals or important aspects of life. But how about the aspects of vegan nutrition? Isn't it extreme to want to limit your diet to plants, while your body also thrives when you consume animal nutrients? Isn't is extreme to want to put your omnivorous human nature in a vegan straightjacket? Maybe this is true from a purely biological perspective, but that would also be true for vegetarianism and even any other cultural curtailment of certain foodstuffs. This can, however, only be considered extreme if one wants to consider human beings as primarily physical beings, instead of thinking, cultural and moral beings.
It is a different matter when it concerns a diet that deliberately acts counter to the biological need for certain nutrients. In the case of veganism this means that neglecting the need for (mostly) vitamin B12 goes too far, but when is this phenomenon still encountered in modern-day vegans? Most vegans that I know make certain that they have no deficits in this area.
Unnecessary use of animals as an extreme phenomenon
Even though you might ask yourself to what extent words as 'extreme' and 'extremist' are truly enlightening, we could fling the ball back. It is far-reaching to close your eyes to the violation of animal rights when it comes to meat, fish, seafood, dairy, leather, wool and honey. These days it is virtually impossible to be completely uninformed about these issues. The reasons given for unnecessary use of animals are all fallacies. It is, for example, impossible to morally maintain that a pleasant flavor is more important and should carry more weight than the life of an animal. How extreme is it really to continue to use animals for your own pleasure without this being really necessary?
Imagine a fictitious tribe of cannibals that has become so fond of the taste of human flesh that it wants to (literally) adhere to its old traditions at all cost. Imagine that they would even employ the latest technology. They would keep their fellow men in accommodations that are far too small and 'humanely' slaughter them at a young age. How extreme can we call this behavior? The most important difference is of course that here it concerns humans and not 'just' animals. But this uncovers one of the most important sources of the reproach of extremism: The self-evident speciesism. For the time being, consuming meat and dairy products is completely normal and therefore it is little effective to expose it as extremism. It suffices to raise the question how far it goes to sacrifice animals for human pleasure.