Within the wide divergence of opinions about the philosophy of probability, there is one significant bifurcation that has been recurrently acknowledged since the emergence of probability around 1600 (Hacking, The emergence of probability: a philosophical study of early ideas about probability induction and statistical inference. Cambridge University Press, Cambridge, 1975). Hacking describes this duality of probability as the "Janus-faced nature" (p. 12) of probability, explaining "on the one side it is statistical, concerning itself with stochastic laws of chance processes' (ibid.); and "on the other side it is epistemological, dedicated to assessing reasonable degrees of belief in propositions quite devoid of statistical background" (ibid.). Although the phrase "Janus-faced" continues to be used throughout probability (related) literature, the terms used to describe the two different faces (i.e., the different theories or interpretations) of probability have not been similarly adopted.