That explanation is then considered the most probable, or best, of the alternatives, and it becomes a working hypothesis until further evidence arises which makes it less tenable.
Below are eighteen facts about the world, some of which are scientific and others of which might be called existential. There are basically two competing metaphysical explanations for these facts in Western culture - naturalism and theism.
Naturalism asserts that the universe and everything about it is the product of purely unguided, random processes. Theism asserts that the universe and everything about it is the product of an intelligent, intentional mind or agent.
We must approach the evidence objectively, that is with no a priori assumptions about the truth or falsity of either explanation, and then ask which of the two explanations do these eighteen facts mesh with most comfortably.
Do they conform best with the view that everything is a product of blind forces and serendipity, or are they best explained by assuming the existence of a transcendent, intelligent agent?
Remember, no a priori assumptions about which of the two alternatives is correct are permitted.
Here are the eighteen with a brief elaboration on each:
- The fact that the universe had a beginning: What caused the universe to come into being when it did? Could it have "just happened"?
- The fact of cosmic fine-tuning: Is it just a lucky accident that there are dozens of forces, constants and other parameters that are calibrated to within astonishingly precise limits such that were it otherwise either life or the universe itself could not exist?
- The fact of the ubiquity of biological information: It's the uniform experience of human beings that information is the product of a mind. How, then, did the information in DNA and other macromolecules arise?
- The fact of human consciousness: How does brain matter by itself generate meaning, sensation and awareness?
- The fact that mathematics can explain much of the world and that we can comprehend math: Is it just a coincidence that the world is explicable in the language of math? How did we evolve the ability to do higher math when such an ability had no survival value?
- The joy we experience when we encounter beauty: Why does beauty, whether visual or auditory, affect us?
- The fact that we believe human reason to be generally reliable: If reason evolved to aid in survival then it doesn't necessarily produce true beliefs, especially metaphysical beliefs, so why should we trust it?
- Our sense that we have free will: If we're just a collocation of atoms governed by the principles of chemistry where does the powerful intuition that we're in some sense free to choose and responsible for our choices come from?
- Our desire for answers to life's deepest questions: Why would the evolutionary process produce in us a desire for answers which are completely unnecessary for survival?
- Our sense of moral obligation: Where does our sense that we have a duty to do some things and to avoid others come from? Why do we think this sense of duty is somehow binding upon us?
- Our sense of guilt/regret: If nothing is really right or wrong why do we have a sense of guilt when we engage in certain behaviors? Why do we feel guilt if we're not guilty and what does it even mean to be guilty?
- Our belief in human dignity: If we're just an animal, an ephemeral product of chance and physical law, from whence comes the notion that we have dignity?
- Our belief in human worth: Where does the notion that we have worth come from? Evolution?
- Our belief that there are basic human rights: Who or what decides what these rights are and confers them upon us?
- Our desire for justice: Why have we evolved a desire for justice if there is no such thing, at least not in an ultimate sense?
- Our need for meaning and purpose: Why, if we're the product of natural selection and genetic mutation, do we yearn for a deeper meaning to life beyond mere reproduction?
- Our belief that we have an enduring self: If all we are is a "pack of neurons" (Francis Crick) what is it about us that makes us think we're something more, something that perdures through time?
- Our desire to survive our own death: If death is just a natural part of life why do we have a desire for something more?