Your question is best addressed by considering a spectrum of what's possible. An example is provided by Oscar Handlin's (1915-2011) benchmark book, Boston's Immigrants, 1790–1865 (1941). Handlin was old-school, and his classic study of immigration is an eloquent expression of von Ranke’s view of history as a discipline. Handlin’s work is full of insights, and he draws upon dozens of examples – real people – to serve as evidence of how their lives supported his view of the past. Information (the science of the equation) fitted into what is really a literary masterpiece (the art end of the spectrum) full of the insights that Handlin drew from the sources he considered.

Handlin’s student, Stephen Thernstrom (b. 1934) emerged as a “cliometrician” – someone who relied on statistics to describe the past. His major work, The other Bostonians; poverty and progress in the American metropolis, 1880-1970 (1973) is a response to Handlin, a declaration of why and how the discipline of history should move to the scientific end of the spectrum. His book describes the immigrant experience in broad statistical terms. The only people he names by name were other historians (I believe this to be true – I searched in a previous decade and could not find any living breathing people other than historians!). Thernstrom does not name the immigrants. They are part of large group, which are considered statistically but not individually. Thernstrom sterilized the past so it could be studied scientifically. One will find no art here – except for the art that one can always find in an elegant equation.

When I set out to write my work on Nevada’s Comstock Lode – The Roar and the Silence: A History of Virginia City and the Comstock Lode 1998), I considered these two possibilities. The story of mining in the American West is largely that of immigration, so I looked to Handlin and Thernstrom for guidance. Before me, Wilbur S. “Shep” Shepperson had published Restless Strangers; Nevada's Immigrants and Their Interpreters (1970). Shep was of the Handlin mould. Shep was an eloquent writer, but he always played loose with the facts. His was a purely artistic depiction of Nevada (largely Comstock) immigration. And it was full of bullshit. But it was very well written.

So, what was I to do? I had at my disposal a digitized version of key federal censuses of the Comstock Mining District. This gave me an opportunity to drill down and understand the population of the place and to describe it as a cliometrician – with the sterility of a scientist. The problem with that was that I enjoyed Handlin and appreciated his kindness to the people of the past. I learned from Thernstrom, but there was no warmth there. One may learn a great deal from Thernstrom – but one will not have a good time in the process!!!

I resolved to synthesize the two possibilities. I used Thernstrom’s method to describe what was happening statistically, and I tried to draw inspiration from Handlin’s style of presentation. Real people talk in the pages of my book, even while they are fitted into the statistical modelling. I tried to occupy that middle place on the spectrum between art and science.

Others can decide if I succeeded, but the question you present was always on my mind as I wrote. Frankly, it remains persistently present with me even today as I write.

If this doesn’t qualify as an informed enough answer for the sub I understand:

An important starting place is defining science and art, and considering why and when they separated. I am not as familiar with the philosophy around this topic or the history of this development but I enjoyed Stephen Bann’s book Romanticism and the Rise of History which gives a great introduction to when the current form of popularized history and historical study took shape, and also touches lightly on the separation of science from religion and how history moved from religion and science to something else entirely. I’d love to hear thoughts on the book or better recommendations from someone more familiar with the topic and period.

Personally, I consider history a study. A position I take on most things that require skill, time, interest, passion, or even talent to develop. If we define science as something repeated, evidence-based, and tested, history is a science. If we define art as something intuitive, unique to every creator and every observer, emotional, contextual, and community-based, history is also an art. I don’t find either science or art to be encompassing terms, and those definitions are certainly not overly developed but rather rough stabs at what I instinctively attribute to our social definition of the words. I think every skill takes both science and art to develop, and history is no exception.