In religious debates, one often hears what might be called the Newton argument: Isaac Newton believed in God, therefore religious belief is reasonable (or it doesn't conflict with science, or something similar). The most recent manifestation I've seen is in a post by Mark Kleiman attacking PZ Myers. (For those interested in what I think on the main points of the exchange: PZ is wrong to paint believers with so broad a brush, but right on the validity of claiming God is "really" a metaphor.)
For anyone who knows Newton's biography beyond the fact that he invented classical mechanics and calculus, the Newton argument is obvious baloney. Newton was also big on alchemy and numerology, in fact it is believed that his writings on these subjects outweigh his legitimate scientific writings. This doesn't make alchemy or numerology valid. QED.
Tags: Newton, God, alchemy, numerology, science, religion, PZ Myers