Doubt in Favour of the Defendant, Guilty Beyond Reasonable Doubt their private advantage to the public: if all historians that write of Tiberius, say that Tiberius did so, it is extremely probable. And in this case, our assent has a sufficient foundation to raise itself to a degree which we may call confidence...87 According to Locke, the highest level of probability was “so near to certainty” and commanded universal assent. The lower levels of probability were “confidence,” “confident belief,” and “mere opinion.”88 The level of assent was to be determined according to “the different evidence and probability of the thing: which rises and falls, according as those two foundations of credibility, viz. common observation in like cases, and particular testimonies in that particular instance, favor or contradict it.”89 Locke’s systematization became so influential that the first treatises on legal evidence built on Locke’s ideas.90 Another influential philosopher of the Age of Reason, who classified levels of certainty, was Bishop John Wilkins (1614 – 1672). In his treatise Of the Principles and Duties of Natural Religion (1675), Wilkins distinguished between “Knowledge or Certainty,” and “Opinion or Probability.”91 “Knowledge or Certainty” was “[t]hat kind of Assent which doth arise from such plain and clear Evidence as doth not admit of any reasonable Cause of doubting.”92 According to Wilkins, there were three kinds of certainty: physical, mathematical, and moral.93 Physical knowledge or certainty depended on the “Evidence of Sense, which is the first and highest Kind of Evidence of which human Nature is capable.”94 Mathematical certainty could be established by logical demonstration, such as geometry proofs.95 Moral certainty: [Has] its Object such Beings as are less simple, and do more depend upon mixed Circumstances. Which though they are not capable of the same kind of Evidence … so as to necessitate every Man’s Assent, though his Judgment be never so much prejudiced against them; yet may they be so plain, that every Man whose Judgment is free from prejudice will consent unto them. And though there be no natural Necessity, that such things must be so, and that they John Locke, Of the Degrees of Assent in An Essay Concerning Human Understanding, Bk. IV, Ch. XVI, section 6, 7(II) (1690) (hereinafter “Locke”), available at http://enlightenment.supersaturated.com/ johnlocke/BOOKIVChapterXVI.html (last accessed 14 April 2016). 88 Locke, sections 6, 7(II), 9. 89 Locke, section 9. 90 Shapiro, Doubt, p. 8, suggesting that Locke’s highest level of probability was what others later called “moral certainty,” and that it was determined by the weight of the evidence. See also infra subsection Reasonable Doubt in Treatises. 91 John Wilkins, Of the Principles and Duties of Natural Religion 5 (London: J. Walthoe, J. Knapton 1734) (hereinafter “Wilkins”) (emphasis in original). available at https://archive.org/details/ ofprinciplesduti00wilk (last accessed 14 April 2016). The first edition was published in 1675 after the author’s death. 92 Wilkins, p. 5 (emphasis in original). 93 Wilkins, p. 5 (emphasis in original). 94 Wilkins, p. 5 (emphasis in original). 95 Wilkins, p. 6. 87 30