Originally recorded by Larry Meredith (1970).
Hit versions by Shirley Bassey (UK #6 1971) and The Carpenters (US #3/MOR #1/UK #18/CAN #7 1971).
From the wiki: “‘For All We Know’ is a popular song written by Fred Karlin, Robb Wilson (Robb Royer) and Arthur James (Jimmy Griffin) for the 1970 film Lovers and Other Strangers, and for which it won the 1971 Academy Award for Best Original Song. It was originally performed by Larry Meredith for the movie soundtrack. Two of the songwriters, Royer and Griffin, were co-founders of the band Bread with David Gates.