Now we have more direct evidence.1 The Israel National Library has just put a pile of Newton's writings on line [Israel National Library uploads trove of Newton's theological tracts ]. We get to see direct example of how Newton thinks like a scientist.
My favorite is Newton's predictions about when the apocalypse will take place. He starts his calculation with the crowing of Charlemagne as Holy Roman Emperor in 800 AD and goes downhill from there [Newton on the date 2060 (early 18th century)].
In the instance displayed on this manuscript folio, Newton calculates a tentative date using the 1260 days (taken to be years) from Daniel in part to counter the claims of some of his contemporaries, who claimed that the end would come in the seventeenth or eighteenth century. Newton stood apart from contemporary interpreters who were predicting the imminent restoration of the Jews, the fall of the Catholic Church and the Second Coming of Christ. Nevertheless, Newton’s own fervent belief in these prophetic events is not in doubt. The abbreviation “A.C.” stands for Anno Christi (“the year of Christ”).There's lots more where this came from but I don't want to embarrass the Newton supporters any further.
So then the time times and half a time are 42 months or 1260 days or three years and an half, reckoning twelve months to a year and 30 days to a month as was done in the Calendar of the primitive year. And the days of short lived Beasts being put for the years of lived [sic] kingdoms, the period of 1260 days, if dated from the complete conquest of the three kings A.C. 800, will end A.C. 2060. It may end later, but I see no reason for its ending sooner. This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fanciful men who are frequently predicting the time of the end, and by doing so bring the sacred prophesies into discredit as often as their predictions fail. Christ comes as a thief in the night, and it is not for us to know the times and seasons which God hath put into his own breast.
By way of contrast, the real greatest scientist who ever lived was a non-believer who never would have treated the Bible as a scientific authority.
1. The information isn't new. It's just that we can now see for ourselves that Isaac Newton was remarkably unscientific in most of his writings.
P.S. Some losers are going to argue that Newton was still the greatest scientist and we should ignore the fact that his religious beliefs made him write many stupid anti-science treatises. That's like saying that Young Earth Creationists (like Newton) can be good scientists even though they believe the Earth is only 6000 years old.