How do we know what to believe? We have experience of the senses which bring us most of our understanding of reality in the environment. Science is based on this observation. High probability of observing bring us scientific laws. Next we have reason which uses information we believe to come to a reasonable expectation. This type of rational thinking is not always based on tested facts but rather beliefs passed down to us.

Credence requires an honest evaluation of evidence and sorting it out to the most probable useful conclusion. How do you do it? How much do emotions count?