History: art or science?

I love a good murder mystery and a historical whodunit as much as anybody else. It transpires that what I truly love however is unbiased, critically appraised deep historical research. It's an interpretation of presentable/provable facts I'm looking for, not supposition based on circumstantial evidence.

We can all maintain our personal theories on why things happened or if indeed they did happen at all. The key factor for any historian worth their salt though is to be able back those assertions with discernibly unbiased and acceptable evidence.

Take this recent example;

http://www.newstatesman.com/culture/2013/03/new-evidence-was-richard-iii-guilty-murdering-princes-tower

An interesting article and an interesting theory. Based however on a lot of circumstantial evidence and supposition. Amy Licence may well be right, I for one don't know either way if Richard was involved in the death of his nephews. For that mater I don't know for a fact that they were killed. Its never been proven either way. Which is where supposition comes in.

I enjoy strongly opinionated historians who will fight their cause. Just as long as they can use evidence to justifiably support that cause. Otherwise what we have is an artwork of woven together ideas and suppositions underpinned by history akin to hearsay. This just won't do! We came through the Enlightenment for a reason; let's take a rational reasoned approach to everything that's appropriate to do so (history certainly is) and be absolutely certain of our facts.  Like scientists sometimes we'll have to say 'we just don't know'. Perhaps it will be less exciting and sell less books but it'll be intellectually more honest and benefit the discipline of history more in the long run.

So history art or science? The best history has a scientific unbiased approach to the research and then presents that in an artistic and engaging way.