Jack Irving Seltzer, formerly of Brookline and South Dennis, died Monday at Epoch Senior Living in Brewster at the age of 102. He was recently predeceased by his loving wife of 68 years, Elaine Eldredge Seltzer, and daughter Deborah Lee Seltzer of Pittsburgh PA. Jack was born in Boston to the late Rabbi Solomon H. Seltzer and the late Edith Abramson Seltzer. He is survived by his children David Stephen Seltzer and his wife Ann Moitoza Seltzer of Davis CA, Susan Seltzer Bourget and her partner Craig Nealley of Duxbury, and Edith Seltzer Geoffrion, her husband Raymond Edward Geoffrion, and their children David and Robin of Brewster, MA.After graduating from Boston University with a BA in biology (where he later also received his Masters degree), Jack joined the US Navy and served honorably as Lt. in WWII in the Pacific, earning commendation for his service. At that time, Jack also met his wife Elaine, a fellow Naval officer.An early career in photography combined with a love of science led to Jack's pioneering research in the field of medical photomicrography. For many years he owned a popular photo shops in Chestnut Hill and Copley square, but then he changed direction and joined his wife in the field of their greatest love-education. His calling was to be a teacher and mentor; as the son of a rabbi, Jack was always teaching-in and out of the classroom. His official classrooms included public schools in Newton and Wayland and the Maimonides School in Brookline. But there were also college athletic events that he refereed, scout meetings that he led, and summer campers he counseled, and of course the nightly dinner table at home. Jack's unconventional teaching style was creative, fun, entertaining –and as memorable as his constant smile and daily bow tie.After many cruises, and winters in Florida, Jack eventually retired full time with his wife to the family summer cottage on Cape Cod where he enjoyed golfing, family beach outings, and spending time with his grandchildren.A funeral in his honor will take place at 3:30 PM, Thursday April 28 at Doane Beal and Ames Funeral Home, 729 Rt. 134, SOUTH DENNIS, followed by burial at Oak Ridge Cemetery, South Dennis. In lieu of flowers, the family is requesting donations made to Hope Hospice, or to the charity of ones choice.