Yang Wei-cher: From Calculus to the Mother Tongue, the Performing Artist of the Mathematics World

30-Second Overview:
Yang Wei-cher is a legend in Taiwan's mathematical community and the first professor on the National Taiwan University campus to formally advertise a course as being “taught in Taiwanese.” His life is full of contrasts: born into an artistic family, yet devoted to abstract mathematics; a coach for the Mathematical Olympiad, yet an advocate of the idea that “everyone is gifted”; and, in the afterglow of authoritarian rule, one of the bravest voices in the Chen Wen-chen Incident. He constructed a counterexample: Taiwanese can carry professional knowledge; Taiwan simply went too long without using it to think professionally.

1997: A Calculus Storm over “Unconstitutionality”

On October 6, 1997, a battle over language and law unfolded at the Legislative Yuan’s questioning podium. New Party legislator Fu Kun-cheng sharply questioned then Minister of Education Wu Jing, accusing National Taiwan University mathematics professor Yang Wei-cher of adopting a “completely unconstitutional practice” by requiring Taiwanese as the language of instruction in his general education course “Mathematical Methods and Reasoning.” Fu argued that this discriminated against students whose mother tongue was not Taiwanese, and even maintained that “some things cannot be left to university autonomy.” ¹

The source of this storm was a decision Yang made in the fall semester of 1996. Observing that Taiwan’s languages were nearing extinction, and out of concern for local culture, he explicitly marked “taught in Taiwanese” in the course syllabus. Although NTU’s then dean of academic affairs, Lee Si-chen, had commented that “dialects should not be used in class,” Yang believed that the language of instruction fell within academic autonomy and required no approval, so he opened the course as planned. ^{1 2}

This was not only the first NTU course formally labeled as being taught in Taiwanese; it also established a “counterexample.” Yang once said: “As long as I actually do it, they will never again be able to cite a pile of reasons and say that teaching in Taiwanese is impossible!” ³ In 2003, he went a step further by practicing Taiwanese-language instruction in the Department of Civil Engineering’s “Calculus A” course, turning the legend of “teaching calculus in Taiwanese” into one of the warmest historical fragments on the NTU campus.

Family Contrasts: From the Son of a Famous Painter to the Father of a Mathematical Prodigy

Yang Wei-cher’s life trajectory was itself an act of “resistance” against traditional authority. His father was Yang Chi-tung, a renowned Taiwanese watercolorist and educator. Yang Chi-tung had placed great hopes in his son and wanted him to practice medicine. Yang Wei-cher was initially admitted to NTU’s College of Medicine through recommendation, but after three years of study, finding it incompatible with his interests, he secretly withdrew from school without telling his father and retook the entrance examination, ultimately entering NTU’s Department of Mathematics. Yang Chi-tung did not learn of this major turn until he saw it reported in the newspaper. ⁴

📝 Curator’s Note: Although he departed from his father’s expectation that he become a physician, Yang Wei-cher inherited his father’s artistic genes in another way: he treated “teaching” as a form of performance art.

This respect for talent also extended to the next generation. His son Yang Bo-yin was one of Taiwan’s well-known gifted students who skipped grades, graduating from NTU at age 18 and later becoming a noted mathematician; ⁵ his daughter Yang Han-ru, meanwhile, moved entirely outside mathematics and the sciences to become a well-known Kunqu performing artist. In Yang Wei-cher’s family, logic and art, tradition and modernity, coexist with one another.

Steadfast Resistance: A Voice of Justice in the Chen Wen-chen Incident

In the history of NTU’s Department of Mathematics, the Chen Wen-chen Incident remains a permanent wound. As Chen Wen-chen’s teacher during his years at NTU, Yang Wei-cher showed tremendous courage after the incident occurred. In the chilling political atmosphere of the time, he publicly said he felt “contempt” for the NTU president’s indifference. ⁶

He recalled that when the Chen Wen-chen Incident occurred, he was inside the examination compound, and whenever he thought of it he felt unbearable pain. ⁷ Many years later, when students and alumni fought to establish a memorial at the site where Chen was killed, Yang proposed the first draft of the inscription: “In memory of a brave man who firmly resisted state violence.” The sentence mourned his student, while also condensing Yang’s lifelong posture of resisting authoritarianism and insisting on autonomy. ⁸

A Performing Artist: Shorts, Bicycle, and the Mathematics Lecture Hall

On the NTU campus, Yang Wei-cher’s image was unmistakable: wearing shorts year-round, riding a bicycle, and moving casually along Royal Palm Boulevard. He treated the lectern as a stage, not as a place for dull, routine teaching.

To allow a nearly visually impaired student to “touch mathematics,” he once assembled regular polyhedron models by hand from sheets of cardboard; he would also take a honeycomb from a drawer and explain to students how the hexagon became nature’s geometric miracle for saving space. ³

He refuted the prejudice that “Taiwanese cannot express technical terminology.” In his view, the logic of subjects such as mathematics, engineering, and medicine is universal, so teaching calculus in Taiwanese is actually simple; the truly difficult courses are general education courses, because they require weaving everyday contexts with rich Taiwanese vocabulary, like an “old grandfather telling stories.” ³

A Driver of Gifted Education: Everyone Can Be Gifted

Another major contribution Yang Wei-cher made to education in Taiwan lay in gifted education and the promotion of the International Mathematical Olympiad (IMO). He long served as a training instructor for Taiwan’s IMO team and was an initiator for many mathematically talented students. ⁹

Yet his definition of “gifted” differed from popular imagination. In the series Professor Yang Wei-cher’s Mathematics Lecture Hall, which he coauthored with Wu-Nan Book, the core idea was that “everyone is a gifted student, and everyone can be a gifted student.” ¹⁰ He advocated that mathematics should be “read forward,” emphasizing deep conceptual understanding and flexible application rather than rote memorization of problem types. This “Yang style” of education was, in essence, an encouragement for students to break frameworks and dare to challenge authority.

Later Years and Legacy: Regretting That He Did Not Start Earlier

After retirement, Yang Wei-cher remained active in mother-tongue promotion and public affairs. At the end of 2023, still in his eighties, he was invited to NTU’s College of Liberal Arts to give an entirely Taiwanese-language lecture exploring politics and institutions from a mathematical perspective. ¹¹ Looking back on his teaching career, the sentence he most often repeated was: “I regret that I did not teach mathematics in Taiwanese from the very beginning.” ³

He admitted that when he first returned to Taiwan to teach in 1971, he too was in an “unawakened” state and taught in Mandarin. His persistence in the second half of his life was, in effect, compensation for those years of silence. He searched through Taiwanese dictionaries, taught himself romanization, and even personally compiled Taiwanese-language mathematics teaching materials, all to prove that Taiwanese could discuss not only everyday life but also carry the most rigorous scientific logic.

Yang Wei-cher’s very existence poses a profound question to Taiwan’s cultural subjectivity. With a lifetime of work, he told us: when a society’s language withers until it can only talk about eating, drinking, defecating, and urinating, the problem is not the language, but the collective abandonment by intellectuals of the ability to think in the mother tongue.

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