Different types of lines can depict various emotions. Jagged lines can be seen as harsh and evil, curvy lines relaxed and safe, or straight lines stable and calm.
In Van Gogh's Starry Nights there is a lot of emotion and mostly conveyed through the types of lines he uses. The swirling lines of the night sky are all rounded, making it seem majestic. We feel guided by the lines drawing our eyes all around the painting as a whole. The building in the small town at the bottom of the painting are largely composed of small straight lines, conveying a sense of stability and calm. The tall cantered lines of the small steeple even make us feel somewhat safe. The large black figure on the left has jagged, pointy tips with chunkier, darker lines. This conveys a more ominous feeling, seeming dark and threatening.