[3] He is most well known for his advocacy of rural residents around the Watarase River whose health and livelihoods were negatively effected by pollution from the Ashio Copper Mine in the 1880s.
He was raised by his father, the headman of Konaka Village and principal of the Jōrenji Temple school in present-day Sano, Tochigi.
[8] The end of the Tokugawa era saw major changes in Japanese economic system, which allowed for a national market, domestic trade, and the commercialization of agriculture.
[9] As a headman, Tanaka rose up and challenged the feudal system made up of shogun government controlling the domain which encompassed his village.
He was forced to maintain to stress positions for extensive periods of time and survived for 30 days by licking a stick of dried bonito.
[12] Tanaka was convicted of, "...disturbing the peace of the Fief, betraying the trust of his position (as Headman of Kanaka), plotting in a nefarious manner and submitting presumptuous petitions...".
[14] He was placed in Iwate prison where he studied Jean Jacques Rousseau’s (1712–78) Du Contrat Social (1762) and Samuel Smiles’s (1812–1904) Self-Help (1859).
[17] This schema nationalized rivers and required a village called Yanaka to be demolished to make way for a flood control reservoir.
[19] Tanaka is best known for his advocacy in connection with the pollution caused by waste from the Ashio Copper Mine owned by Furukawa Ichibei.
[25] The effects on the communities and industries in the area were deleterious, “Copper, arsenic, mercury and a host of other pollutants from the Ashio mine located at the headwaters of the Watarase river entered the river and destroyed significant agricultural, fishing and artisanal (silk, indigo) industries in the watershed.”[26] In 1891, after having been elected to the National Diet via Japan’s first parliamentary elections, Tanaka gave a famous speech questioning why the Meiji government had not suspended Ashio's operations based on the Meiji Constitution’s guarantees of individual property rights.
[27] An activist uprising consisting of farmers, fishing households, soil scientists, Tokyo intellectuals, nationalists, anarchists, Christian socialists, and early Marxists developed against the environmental pollution caused by the mine.
The order directed Furukawa, owner of the mine, to make mitigation efforts to control erosion and prevent waste from getting into the Watarase River.
[34] Tanaka’s political activism against the 1896 River Law led to the development of his ecological philosophy and terminology; poison (Doku) and flow (Nagare).
This philosophy is described by Robert Stolz as an "...ecological theory of society based on the twin processes of nature..."[35] In relation to the 1896 River Law, which sought to remake the Kanto Plain, Doku represented the unnatural damming of the river and the inevitable build-up of poisons in the watershed, while Nagare represented the natural way of things.
"[18] According to Yanakagaku thought, the Japanese state's construction of dams and sluices inhibits the natural flow of the river, thereby increasing Doku.
His last possessions were an unfinished manuscript, a book of the New Testament, handkerchief paper, river nori, three pebbles, three diaries, a bound copy of the Meiji Constitution, and the Gospel of Matthew in a cloth bag.