Nikola Tesla is often typed as INTJ in modern MBTI discussions, although INTP and INFJ have also been proposed. When examined through the framework of Carl Jung’s Chapter X of Psychological Types, INTJ provides a particularly convincing four-letter MBTI equivalent because Tesla demonstrated intense inward concentration, visionary imagination, conceptual independence, and an extraordinary ability to transform internally developed ideas into technological possibilities. However, Jung did not use the MBTI system, and Tesla cannot be typed with certainty from historical records. This analysis is therefore a retrospective interpretation of his documented personality, working methods, writings, and achievements. The dominant function associated with the modern INTJ type is Introverted Intuition (Ni). Jung described the introverted intuitive type as someone whose psychological perception is directed toward inner images, possibilities, symbolic relationships, and underlying processes that may not be immediately apparent through ordinary sensory observation. Tesla strongly exemplified this orientation. His approach to invention was famously imaginative and internally visual. Rather than immediately constructing physical prototypes, he could mentally develop machines, mechanisms, and experiments in extraordinary detail. Tesla's ability to visualize inventions before physically constructing them illustrates the inward and conceptual character associated with Introverted Intuition. He often described experiencing ideas as vivid internal representations. This allowed him to mentally manipulate mechanisms and anticipate how they would function before committing substantial resources to experimentation. His imagination was therefore not merely artistic fantasy; it became a powerful method for technological discovery. Jung emphasized that introverted intuition can perceive possibilities that have not yet become concrete realities. Tesla's career provides numerous examples of this tendency. Alternating-current electrical systems, wireless communication, remote control, and other technologies were initially possibilities existing within his imagination and theoretical reasoning before they became practical demonstrations. His fascination with wireless energy and the future of communication reflected a mind oriented toward what technology could eventually become rather than simply improving what already existed. The auxiliary function associated with INTJ is Extraverted Thinking (Te). Jung described extraverted thinking as an orientation toward objective organization, practical implementation, and the transformation of conceptual principles into external systems. Tesla's inventions demonstrate a strong relationship between internal vision and external engineering. His imagination was supported by rigorous technical reasoning and an ability to express complex concepts through mathematical and physical principles. Tesla did not merely imagine futuristic devices; he worked to establish the scientific and engineering conditions necessary to make them possible. His work with alternating current illustrates this combination particularly well. The conceptual understanding of rotating magnetic fields and polyphase electrical systems could be translated into generators, motors, and distribution technologies. His ability to connect abstract principles with practical mechanisms demonstrates the supporting role of Extraverted Thinking. The Te component also appears in Tesla's preference for efficiency and systematic functionality. He was deeply interested in solving technical problems and eliminating unnecessary mechanical complications. His inventions often sought elegant solutions to practical problems. Even when his ideas were extremely visionary, he generally expressed them in terms of engineering principles and technological applications. The tertiary function associated with INTJ is Introverted Feeling (Fi). Jung described introverted feeling as an internally oriented system of personal values that may remain relatively private. Tesla's public persona was often highly intellectual and controlled, yet his writings and personal statements reveal strong individual ideals. He possessed a pronounced sense of personal purpose and often described science and invention as serving humanity rather than merely producing financial gain. Tesla's relationship with money illustrates this private value orientation. Although financial difficulties affected his career, he frequently prioritized experimentation and scientific achievement over conventional commercial success. His commitment to technological progress appeared deeply personal. He often pursued ideas because he believed they represented meaningful contributions to civilization, even when immediate financial rewards were uncertain. The inferior function associated with INTJ is Extraverted Sensing (Se). Jung regarded the inferior function as the least conscious and least naturally developed psychological function. For an INTJ interpretation, Extraverted Sensing concerns direct sensory engagement with immediate reality and responsiveness to physical experience. Tesla's personality often appeared more comfortable in the realm of imagination and conceptual thought than ordinary social or sensory life. Nevertheless, his work required extraordinary engagement with physical reality. Electrical experiments, mechanical systems, laboratory demonstrations, and technological prototypes demanded precise interaction with the material world. Tesla was capable of intense sensory experimentation, particularly when demonstrating his inventions. His famous electrical demonstrations show that his abstract ideas could become spectacular physical experiences. However, his relationship with practical reality was sometimes complicated. Tesla's later projects frequently became increasingly ambitious, and some ideas were pursued despite significant financial and engineering difficulties. This can be interpreted as an imbalance between an exceptionally powerful internal vision and the limitations of immediate external circumstances. His imagination could move considerably faster than available technology, funding, or infrastructure. Some typologists classify Tesla as INTP because of his analytical intelligence, scientific curiosity, and independence from conventional institutions. This interpretation is plausible. However, Tesla's psychological style often appeared more convergent and visionary than exploratory. He frequently pursued a particular technological possibility with extraordinary persistence, rather than simply investigating ideas without a predetermined direction. His internal visions were often unusually strong and specific, supporting Introverted Intuition as the dominant function. Others identify Tesla as INFJ because of his humanitarian ideals and visionary language about humanity's future. However, his primary mode of understanding the world was strongly technical and conceptual. His humanitarian values appear to have supported his scientific vision rather than replacing it. His work was fundamentally concerned with discovering principles and transforming them into technological systems, making an INTJ interpretation more convincing. Tesla also differed from a stereotypically practical sensing type because he frequently imagined technological possibilities far beyond the immediate capabilities of his era. His interest in wireless energy, automation, remote control, and global communication illustrates a persistent orientation toward future technological possibilities. He was not simply responding to existing engineering problems; he repeatedly attempted to anticipate what civilization might eventually need. Viewed through the framework of Chapter X of Psychological Types, Nikola Tesla most plausibly corresponds to the modern MBTI type INTJ. His extraordinary internal visualization and future-oriented technological imagination reflect dominant Introverted Intuition, while his ability to convert those visions into engineering systems demonstrates auxiliary Extraverted Thinking. His strong private ideals and commitment to scientific progress correspond to tertiary Introverted Feeling, while his sometimes complicated relationship with practical limitations reflects the inferior position of Extraverted Sensing. Although no historical figure can be typed with absolute certainty, INTJ provides a coherent interpretation of Tesla's intellectual independence, visionary imagination, engineering discipline, and lifelong pursuit of technological possibilities according to the broader framework established by Carl Jung in Chapter X of Psychological Types.