John Brockman asked dozens of scientists and other intellectuals to state a proposition you believe is true, even though you cannot prove it. Not many of the answers deal with economics, and those that do strike me as hostile without being informative. Nonetheless, it is an interesting feature.
The answer given by physicist Leonard Susskind (scroll down after you follow the link) is worth quoting to my statistics students.
I'm absolutely certain the laws of large numbers—probability theory—will work and protect me. All of science is based on it. But, I can't prove it and I don't really know why it works.
You have to read Susskind's entire piece to appreciate it.
Several interesting answers concern self-deception. For example, John R. Skoyles writes (again, scroll down after you follow the link),
Healing professionals—healers, shamans, witch doctors and medics—exist in all human cultures.
...The rituals and quackery of healers might have not worked but they certainly made a patient feel they were in the hands of an expert. That gave a healer great power over their patient. As noted, many of the body's own "treatments" are used on a precautionary basis so they can be stopped without harm. A healer could do this by applying an impressive "cure" that persuaded the body that its own "treatments" were no longer needed. The body would trust its healer and halt its own efforts and so the "illness". The patient as a result would feel much better, if not cured. Human evolution therefore made doctoring more than just a science and a question of prescribing the right treatment. It made it also an art by which a doctor persuades the patient's body to offload its decision making onto them.
Perhaps what I think of as mental illness in the way that people approach health care in fact is derived from this desire to offload decision-making to others.
Skoyles appears to be saying that people sometimes need to be told when to not feel pain. Green Bay Packer star Jerry Kramer used to joke about the healing powers of coach Vince Lombardi, but perhaps Lombardi was performing the same function as many doctors.
For Discussion. The placebo effect would seem to support Skoyles' hypothesis. What other evidence is there for and against?