Holism

Holism (全体論) is the idea that natural systems and their properties, should be viewed as wholes, not as collection of parts. This often includes the view that systems somehow function as wholes and that their functioning cannot be fully understood solely in terms of their component parts. Holism defines that whole entities, are fundamental components of reality and have an existence other than as the mere sum of their parts.

It encompasses derivative theories such as the Gaia theory. In the Toaru Majutsu no Index storyline, it is mostly referred to its explanation in the development of another form of esper.

Holistic esper
The Holistic esper (全体論の超能力者), is an esper that is developed through the principles of holism. There is currently no person that has achieved becoming a holistic esper, however, efforts of GREMLIN, and its leader, the Majin Othinus, has made considerable progress into its realization.

Principles
Holistic espers work in reverse to regular espers. The espers of Academy City are based on quantum theory, where powers are formed from their Personal Realities, which is based on controlling their microscopic observations of the world, and then effects can be generated in the macroscopic world. Unlike Academy City espers, holistic espers are based on major changes in the whole "system", the macroscopic world, to create a microscopic effect, which is in this case, their powers.

Due to its incredibly roundabout nature, and despite the incredible change that has forced that power upon the esper, since the event required for the esper to attain powers are incomprehensible or unnoticeable to the esper, an esper of holism, might only reach Level 2 or 3 based on Academy City's scale.

Baggage City experiment
As part of their plan, Othinus chooses Baggage City as a basis of an experiment regarding holistic espers. Before she could create a holistic esper, GREMLIN wanted to determine if a supernatural phenomenon would occur when the world was greatly distorted.

Here, using Kihara Kagun to make the inevitable clash between Baggage City and Academy City favorable to GREMLIN's odds and the experiment, he made a few adjustments, as well as a few more for the sake of his revenge. In Baggage City, Othinus wanted to see if the exceedingly large scale battles would cause exceedingly microscopic changes. This is somewhat similar to the Level 6 Shift, where Accelerator was pitted battle after battle in the hopes of him achieving SYSTEM.

This was an experiment to develop esper powers from the result of the battles. If the experiment would show that a small phenomenon caused by a major distortion, then GREMLIN would now begin in altering a candidate's brain to develop an actual holistic esper, most likely similar to the Power Curriculum Program of Academy City.

The results of the holistic experiment showed promise, making Othinus proceed in her plan, since after Kamijou Touma entered Baggage City, his Imagine Breaker negated something that was negatable. The experiment, drew those who were involved in the distortion and the battles, were drawn into the future where the result of the holistic experiment existed. As such, despite the experiments success, Baggage City, the setting of the experiment, became the a place where the laws have been replaced that would allow tragedies to occur more easily, this being the microscopic supernatural phenomenon.

Baggage City Arc
The first mention of a holism and a holistic esper is during the arc. Here, several deaths were indirectly caused by the supernatural phenomenon that Othinus wanted to occur as a result of the battles. At the end, and despite Touma's arrival, Othinus concludes the experiment as a success, and proceeds with the plan, with the next part being in Academy City within the Windowless Building.

Ichihanaran Festival Arc
During the Ichihanaransai, GREMLIN attempted to acquire Fraulein Kreutune, a being able to withstand modification and untainted by magic and science, in order to turn her into a holistic esper. Though the attempt failed and Fraulein Kreutune ended up in a state where she couldn't be used, they acquired the organs of the original Kakine Teitoku, which could be used to create a suitable substitute.

Magic God Othinus Arc
After awakening him, Othinus had Kakine create a holistic esper specimen using his ability, which was then used in an attempt to manufacture Gungnir. The specimen started collapsing towards the end of the process but, with some intervention from Othinus, it managed to fulfill its role before its destruction.