The scholastic realist says, “[…] there are real laws (or necessities,) and real possibilities. They are not actual: they do not exist: but they are not figments. They are such as they are whether you and I think them to be so, or not. The future does not exist. But it is really true that if I find the air in my study stuffy, I can open the window.”
http://www.commens.org/dictionary/entry/quote-notes-portions-humes-treatise-human-nature-2