Scientific Theory, Beliefs, Scissor Value Test and Single Event Inference

An ostensibly straightforward question: given an unknown probability distribution, what information can be inferred from a single positive observation, keeps returning in different domains and problems in the modern science, including the anthropic principle in fundamental physics and abiogenesis problem in astrobiology: estimating the unknown, as of present, probability of the emergence of life from non-biological environment. In this work we discuss common assumptions, beliefs and biases in the analysis of single event inference with the conclusion that the standard probabilistic interpretation and deterministic models are the only ones among the considered that have definite scientific value. As well, a test of scientific value is proposed for assumptions not based on existing knowledge, that is, beliefs, that allows to distinguish valuable beliefs with a potential to lead to new knowledge as a result of subsequent trials from those of insignificant value, due to inability to generate new knowledge.