She spent much of her career at the University of Pittsburgh, and was appointed chair of the philosophy department there in September 1999, but died a few months later.

[2] At age 15, and despite activism against the Vietnam War, she was offered a scholarship to study mathematics at the University of Chicago.

[3] Some years later, Horowitz was appointed chair of the Pitt philosophy department, and took up the role on September 1, 1999.

[1][2][3] A lecture in memory of Horowitz by Alexander Nehamas—"The place of beauty and the role of value in the world of art"—was published in Critical Quarterly in 2000.

[8] Colin MacCabe described Horowitz in an editorial for the issue as someone who had no time whatsoever for the pompous or the pretentious; her concern was always with argument and debate, with the elaboration of human knowledge.