Francis William Lawvere, (born Muncie, Indiana, February 9, 1937), died at sunrise on January 23, 2023, aged 85, after a long illness at his home in Chapel Hill, NC. Bill graduated from Muncie Central High School in 1955 after attending Jefferson Township High School, Upland. He became a mathematician and received his undergraduate degree from Indiana University, Bloomington and his Doctorate from Columbia University, New York City. He did his post-doctoral studies at the ETH in Zurich, Switzerland. Bill was devoted to scientific research, education and the democratic renewal of society. He continues to be greatly appreciated for his research insights and his many collaborations in discovering and elaborating a wide array of new concepts in mathematics and several related fields. As one of the leaders in the field of Category Theory, Bill worked to unify and simplify both advanced and elementary mathematics, so that mathematics and philosophy could continue to serve as guides for science and education. He opposed war, supported liberation and resistance struggles of peoples around the world and at home, and encouraged progressive political activities his entire adult life. He stood for free speech and vigorous discussion involving everyone in addressing problems based on theory and a commitment to progress. Bill generously gave guidance and encouragement to undergraduate and graduate students, as well as to researchers in many countries. He wrote several books and many articles representing his research and collaborations with many colleagues. His wife, Fatima, was a constant collaborator in his fruitful career in mathematical education, publishing and lecturing. Bill lectured and collaborated with scientists in dozens of countries and his contributions continue to widely impact several areas of science. Among many recognitions, in 2010, he was proud to have received the "Premio Giulio Preti" prize, awarded by the Regional Council of Tuscany <https://en.wikipedia.org/wiki/Regional_Council_of_Tuscany>, and to have been elected as an American Mathematical Society Fellow in 2012. Additional information and useful links regarding his scientific life can be found at https://en.wikipedia.org/wiki/William_Lawvere. Many of Bill’s discoveries in advanced mathematics had developed as ways to improve teaching and understanding. He taught at the State University of New York at Buffalo for 26 years and retired officially as professor emeritus in Mathematics and Philosophy in 2000. This allowed him to focus on his passion of research and education. If he was whistling in the morning we knew he was contemplating an interesting idea. Earlier in his career, he held positions at various Universities: Portland, Oregon; New York City; Halifax, Canada; Chicago, Illinois; Zurich, Sw itzerland; Aarhus, Denmark; Perugia, Italy; Paris, France; and Sydney, Australia. Bill enjoyed visiting and spoke highly of his childhood farm outsideMatthews, Indiana, the surrounding farms and towns, and especially of his many relations, friends, classmates and influential teachers who had encouraged him throughout his early education. Preceding him in death were his parents, Francis W. and Delight (Moorman) Lawvere, his son, William Nevin Lawvere, his first wife Sybil Lawvere, his sister-in-law Dorothy Lawvere, and his brother Albert Lawvere. He is survived by his beloved life partner of 57 years Fatima Fenaroli Lawvere, now in Chapel Hill, NC; his children, Marco Fenaroli (Medellin, Colombia); John Theodore Lawvere (Tucson, AZ), Philp Lawvere (Angistri, Greece); Danilo Lawvere (Loretta Gmeinder), (Buffalo NY); Silvana Lawvere de Moreno (Adrian Moreno) (Chapel Hill, NC); and grandchildren Edoardo, Odilla and Jamila Lawvere, and Diego Guillermo Moreno. He is also survived by brother Jon Lawvere (Karen Smile); sister LaRea Lawvere Slater (Jim Slater); Gabi Lawvere (Widow of Albert Lawvere), and nieces and nephews (Robin, LaRonda, Nick and Liell Lawvere) all still living on the family farm in Matthews, Indiana, as well as nephew Marcello Fenaroli (Zurich, Switzerland). He was adored by friends, family, colleagues and loving care-givers. They referred to him as a generous spirit and a gentle giant. Until the end, he was always ready with a smile and a thank you. He will be missed. No services will be held at this time, however, several memorial celebrations of life and scientific work are anticipated. Correspondence with family can be sent to his wife Fatima at fatimaylawvere@gmail.com or to 111 East Winmore Ave., Chapel Hill, NC 27516. William Lawvere - Wikipedia <https://en.wikipedia.org/wiki/William_Lawvere> Biography. Lawvere studied continuum mechanics as an undergraduate with Clifford Truesdell.He learned of category theory while teaching a course on functional analysis for Truesdell, specifically from a problem in John L. Kelley's textbook General Topology.Lawvere found it a promising framework for simple rigorous axioms for the physical ideas of Truesdell and Walter Noll. en.wikipedia.org [For admin and other information see: http://www.mta.ca/~cat-dist/ ]