Once there was a highly intelligent turkey that had nothing to do but reflect on the world’s regularities. Morning always started out with the sky turning light, followed by the master’s footsteps,...

Once there was a highly intelligent turkey that had nothing to do but reflect on the world’s regularities. Morning always started out with the sky turning light, followed by the master’s footsteps, which were always followed by the appearance of food. Other things varied, but food always followed footsteps. The sequence of events was so predictable that it eventually became the basis of the turkey’s theory about the goodness of the world. One morning, after more than 100 confirmations of the goodness theory, the turkey listened for the master’s footsteps, heard them, and had its head chopped off. Any scientific theory is modified or discarded upon discovery of contradictory evidence. The absence of absolute certainty has led some people to conclude that “facts are irrelevant because they can change.” If that is so, should we stop doing scientific research? Why or why not?