In his Treatise of Human Nature, published in 1739, the philosopher David Hume wrote that “the minds of men are mirrors to one another, not only because they reflect each other’s emotions, but also because those rays of passions, sentiments and opinions may be often reverberated.” The Stanford Encyclopedia of Philosophy credits this as the first written account of the existence of empathy, the capacity by which “humans can resonate with and recreate [another] person’s thoughts and emotions on different dimensions of cognitive complexity.”

Empathy is a word that has been used a great deal lately. Google’s NGram word usage frequency data tool shows that empathy has never before been so used. By 2019, it appeared in books three times more often than it had been in 2000, and it had already doubled between 1980 and 2000.