1. In a large soup pot, heat the olive oil. Add the bacon, onion and carrots, and cook, stirring frequently, until the onions are completely wilted. Add the garlic, thyme, salt (you can start with the smaller amount and add more later), a few very generous grinds of black pepper, a bay leaf, the cubed potatoes, and the split peas.
2. Pour in the water and bring to a boil, then reduce the heat to a very low boil. Put a lid on the pot, but leave it askew with room for steam to escape, and cook the soup, stirring every once in a while, until the split peas and potatoes are very soft, about 45 minutes.
3. Remove from heat. Pluck out the bay leaf. Puree the soup to whatever consistency you like with a stick blender. (Or you can use a traditional blender, letting the soup cool to room temperature before blending it. Never fill a blender more than half-full with hot liquid, which can be dangerous.) I like mine partially chunky, partially smooth. Add additional water to get to the soup to the consistency that you like, and season with additional salt, if desired.