Eric Jonathan Goldstein was born on August 29, 1928, in New York City.

[4] According to a 2019 critical review of Cassell's work, his views on the nature of suffering were "close to canonical" in the medical community.

[5] Cassell advanced a subjective view of suffering, according to which the condition must be understood by reference to the beliefs and perceptions of the person experiencing it.

[5] In 2001, Cassell published a study in Annals of Internal Medicine that assessed the decision-making capacity of severely ill adults, finding that their decision-making abilities were similar to those of children under 10.

Commenting on his findings, Cassell stated, "I think it's grossly unfair and I actually think it's an abuse of a patient to put someone in a position to make decisions when they don't have the capacity to make them.