Jonas Edward Salk (; October 28, 1914 - June 23, 1995) was an American medical researcher and virologist. He discovered and developed one of the first successful polio vaccines. Born in New York City, he attended New York University School of Medicine, later choosing to do medical research instead of becoming a practicing physician. In 1939, after earning his medical degree, Salk began an internship as a physician scientist at Mount Sinai Hospital.

In 1966, The New York Times referred to him as the "Father of Biophilosophy." According to Times journalist and author Howard Taubman, "he never forgets... there is a vast amount of darkness for man to penetrate. As a biologist, he believes that his science is on the frontier of tremendous new discoveries; and as a philosopher, he is convinced that humanists and artists have joined the scientists to achieve an understanding of man in all his physical, mental and spiritual complexity. Such interchanges might lead, he would hope, to a new and important school of thinkers he would designate as biophilosophers." Salk told his cousin, Joel Kassiday, at a meeting of the Congressional Clearinghouse on the Future on Capitol Hill in 1984 that he was optimistic that ways to prevent most human and animal diseases would eventually be developed. Salk said people must be prepared to take prudent risks, since "a risk-free society would become a dead-end society" without progress. Salk describes his "biophilosophy" as the application of a "biological, evolutionary point of view to philosophical, cultural, social and psychological problems." He went into more detail in two of his books, Man's Unfolding, and The Survival of the Wisest. In an interview in 1980, he described his thoughts on the subject, including his feeling that a sharp rise and an expected leveling off in the human population would take place and eventually bring a change in human attitudes: "I think of biological knowledge as providing useful analogies for understanding human nature.... People think of biology in terms of such practical matters as drugs, but its contribution to knowledge about living systems and ourselves will in the future be equally important.... In the past epoch, man was concerned with death, high mortality; his attitudes were antideath, antidisease", he says. "In the future, his attitudes will be expressed in terms of prolife and prohealth. The past was dominated by death control; in the future, birth control will be more important. These changes we're observing are part of a natural order and to be expected from our capacity to adapt. It's much more important to cooperate and collaborate. We are the co-authors with nature of our destiny." His definition of a "biophilosopher" is "Someone who draws upon the scriptures of nature, recognizing that we are the product of the process of evolution, and understands that we have become the process itself, through the emergence and evolution of our consciousness, our awareness, our capacity to imagine and anticipate the future, and to choose from among alternatives." Just prior to his death, Salk was working on a new book along the theme of biophilosophy, privately reported to be titled Millennium of the Mind.

Using a quote from the above article, answer the following question: Did he write any books on his biophilosophy?
" He went into more detail in two of his books, Man's Unfolding, and The Survival of the Wisest.