Why does my mind change based on thinking, faith, and science? One of the main functions of a mind is to change — constantly — to repair damage and add new thoughts, or to gradually replace old thoughts with new ones in a zero-sum game.
When I first heard about the century-old 4-color map conjecture as a boy, I noted how well it fit a few anecdotal scribbles and then took leap of faith that 4 colors were always enough. A decade later when Appel, Haken and a computer proved it, you could say that my boyish opinion was intact, but my mind was changed — by "facts" (the exhaustive computer search), by "thinking" (the mathematicians, computer and me collectively), and by "faith" (that the program had no bugs and that basic idea of proofs is reasonable). There were false proofs before that, and shorter confirmatory proofs since then, but the best proof is still too complex for even experts to check by hand.
While I rarely change my mind from one strongly held belief to it's opposite, I do often change from no opinion to acceptance. Perhaps my acquiescence is too easy — rarely confirming the experiments with my own hands. Like many scientists, I form some opinions without reading the primary data (especially if outside of my field). Often, the key experiments could be done, but aren't.
A depressingly small bit of medical practice is based on randomized placebo-controlled, double-blind studies. In this age of vast electronic documentation is there a list of which medical "facts" have achieved this level and which have not? Other times experiments in the usual sense can't be done, e.g. huge fractions of astronomical and biological evolution are far away in space and time. Nevertheless, both of these fields can inspire experiments. I've done hands-on measurements of gravitation with massive lab spheres and mutation/selection evolution in lab bacteria. Such microcosmic simulacra "changed my mind" subtly and allowed me to connect to the larger-scale (non-experimental) facts.
All of this still adds up to a lot of faith and delegated thinking among scientists. The system works because of a trusted network with feedback from practical outcomes. Researchers who stray away from standard protocols (especially core evidentiary and epistemological beliefs) or question too many useful facts, had better have some utility close at hand or they will be ignored — until someone comes along who can both challenge and deliver. In 1993 Pope John Paul II acquitted Galileo, of his indictment in 1632, of heretical support for Copernicus‚s heliocentrism. In 1996 John Paul made a similarly accepting statement about Darwinian evolution.
Clearly religion and science do overlap, and societal minds do change. Even the most fundamentalist creationists accept a huge part of Darwinism, i.e. micro-evolution — which was by no means obvious in the early 19th century. Their remaining doubt is whether largish (macro) changes in morphology or function emerge from the sum of random steps — accepting that small (micro) changes can do so? What happens as we see increasingly dramatic and useful examples of experimental macro-evolution?
We've recently seen the selection of various enzyme catalysts from billions of random RNA sequences. Increasingly biotechnology depends on lab evolution of new, complex synthetic-biology functions and shapes. Admittedly these experiments do involve 'design', but as the lab evolution achieved gets more macro with less intervention, perhaps minds will change about how much intervention is needed in natural macro-evolution.
At least as profound as getting function from randomness, is evolving clever speech from mute brutes. We've made huge progress in revealing the communication potential of chimp, gorilla and African Grey parrot. We've also found genes like FOXP2, which affects vocalization in humans and mice and a variation that separates humans from chimps — but not from Neanderthal genomes. (Yes — extinct Neanderthals are being sequenced!) As we test combinations of such DNA differences in primates, will we discover just how few genetic changes might separate us functionally from chimps? What human blind-spots will be unearthed by talking with other species?
And how fast should we change our mind? Did our 'leap' to agriculture lead to malaria? Did our leap to DDT lead to loss of birds? We'll try DDT again, this time restricted to homes and we'll try transgenic malaria-resistant mosquitoes...and that will lead to what? Arguably faith and spirituality are needed to buffer and govern our technological progress so we don't leap too fast, or look too superficially. Many micro mind-changes add up to macro mind-changes eventually. What's the rush?