Every day you probably pour yourself a glass of water without even thinking about it. What could be more prosaic? It's unlikely that you'd describe it as art.
In the right hands, though, water clearly is art: look at these two amazing images from liquidsculpture.com
All three pictures are essentially the same thing: H2O in different contexts. What makes the latter two art is the craft and the creativity the artist has applied.
There are analogies here to outlining a historical novel. I've spent the past fortnight doing some pretty immersive research into the life and times of Louis XIV and the specifics of the Affair of the Poisons. I'd now say that I'm fairly well-informed on the subject, but I'm still a huge leap away from having a story. What I've been doing so far is filling the glass with water: a necessary step in creating anything more ambitious, but not in itself art.
I need now to arrange the water in a way which gives it pattern and meaning, rather than simply presence. However much I know about the Affair of the Poisons, I don't have a novel--and knowing more won't put me any closer to it. I could write down now a detailed timeline (indeed, I've already done so and no, Aliya, it isn't on a spreadsheet...) of sudden deaths, interrogations and executions, but if I used that to construct a prose narrative I'd do nothing but confuse the reader.
The most difficult part of the writing process for me--and this seems even more the case for historical fiction than fantasy--is moving from the mass of background information to a dramatically satisfying organisation of the material. In other words, the part where we find a story. How many viewpoints will I have? Who will they be - La Reynie, the dogged detective who is investigator, judge and jury? Louvois, his boss, motivated more by a desire to outflank his hated rival Colbert than a quest for justice? Lesage, alchemist, conman, fantasist who finds himself in more trouble than he realises? Madame de Montespan, fading mistress of the king; her life would be so much easier if the beautiful young Mademoiselle de Fontanges was off the scene? Primo Visconti, waspish Italian observer of the court scene who enjoys playing the fortune-teller? The Marquis de Termes, his fortune lost in an earlier scandal who kidnaps an alchemist to make him a new one? Or characters entirely of my own devising?
These are the decisions which will make our story: when our glass of water will take on the outline of sculpture.