Magician

A Magician (魔術師) is an individual trained in using magic. Inadequate training leaves these individuals prone to the consequences of unsuccessfully using magic. It has been stated by Index that those without mana cannot perform magic, such as herself. However, all forms of life can produce mana, and Index, however, cannot directly harness mana outside of her John's Pen Mode state.

Principles
The ceremony and practice of magic was created due to "those without talent" wanting to produce the effects as "those with talent". It is stated that the most important part about magic is its proper preparation; magic that is properly prepared allows even talentless middle schoolers to cast spells; the opposite stands true as improper preparation leads to both malfunction and backlash that inflicts damage on the practitioner's brain.

Magicians tend to operate in secrecy and deny the existence of "magic" when questioned. It is because of this that the vast majority of people, such as most espers concentrated in Academy City, are ignorant to their existence; Shirai Kuroko for example, mistook Sherry Cromwell as an esper after the latter summoned a golem to their aid.

Magicians are distinguished from espers due to the former's use of items with occult properties and their capacity to exploit multiple supernatural powers (such as magicians that can use more than one element, as the case of Oriana Thomson). The latter on the other hand can only access one supernatural power, and there is currently no method for accessing more. Although, despite this, esper abilities are versatile, which, provided that the user is competent enough, allows them to be used for various purposes.

History of Western magic
Carving one's magical name to their soul is an activity that has been practiced by western magicians (though seemingly isolated to English magicians) since the 19th century. Their respective magic names are often related to the reason behind their decision to learn magic or the one dream which they would sacrifice their life for. An exception are Saints, who may carve it onto their chest/heart instead, as shown by William Orwell. Stiyl Magnus once said the real reason for having magic names is long forgotten, now it is only used in battle as a gesture to say 'it will now be a fight to the death'.

Western Magicians since the end of the 19th century, according to Tsuchimikado Motoharu, are beings that "whose wishes are not fulfilled, whose prayers to God went unanswered - people who have lost their way and turned towards this back door called Magic". According to him, most magicians are like children in the aspect they fight honorably and let emotion cloud their judgment - whereas other professionals such as soldiers will shoot without remorse; magicians are like "Children who hold knives. And also as Children who have been betrayed by the world, trembling and crying at the same time". As such, magicians have very little loyalty to organizations - they are willing to betray the group to which they are affiliated to if it somehow clashes with their own dreams/goals.

Other magicians (like the Etzali of the Aztecs) might not follow the Western rule of magic names, or became mages for the same reason.

A common pattern followed by European magicians who practice 'modern western magic' is that when they run into a dead-end in their research which can be overcome with their existing resources and discovered that their objective can't be granted with just their own rules, they come to believe that the answers lie hidden in some as yet unseen paradise and seeking them out. Some of the ideas considered by such magicians are somewhat nonsensical, such as finding some strange grand master in Tibet and gaining to the key to the gates of heaven through his teachings, sunken continents and civilizations such as or, or even receiving divine knowledge and wisdom through radio signals from the Sun. With the colonial period, influences from various foreign cultures (from Central and South America, the Pacific Islands, Southeast Asia, India etc) were introduced, however the biggest influence came from, known as the Dark Continent. Being a large place with a melting pot of tribes, cultures and legends, and conveniently located just across the Mediterranean, many magicians have visited it in order to gather information to make a breakthrough, including Aleister Crowley himself.

Types
Western magicians dabble in a multitude of skills to do with magic, such as Alchemy, astronomy, and summoning. Aureolus Izzard was called an "Alchemist" (錬金術師) because that was all he was good at out of the myriad of sub-sets of magic. In Toaru Majutsu no Index, Alchemy in general is useless compared to other magic, and was renowned for being a trick for gullible nobles in the 16th century where they believed turning lead into gold was possible. Ars Magna was an exception in that it held exceptional power.

"Sorcerer" (魔導師) are magicians that have the purpose of spreading magical knowledge with the objective of raising the next generation of mages, according to Stiyl and Tsuchimikado these magicians are normally strong enough to handle the power of a grimoire and use it to teach the magical knowledge to their apprentices, Index also explained them with such characteristics.

"Magic God" (魔神) is the highest possible position available to magicians where the magic of the user is almost considered divine and can overwrite the laws set by common sense. Other positions are possibly other than that, such as "Saint" (聖人) or "The Person Superior to God" (神上), but they cannot be reached by 'normal' magicians and depends almost entirely on factors like talent or birth.