To consider by turning a subject in the mind, and viewing it in its different aspects and relations; to meditate; to contemplate; to theorize; as, to speculate on questions in religion; to speculate on political events.
To view subjects from certain premises given or assumed, and infer conclusions respecting them a priori.
To purchase with the expectation of a contingent advance in value, and a consequent sale at a profit; -- often, in a somewhat depreciative sense, of unsound or hazardous transactions; as, to speculate in coffee, in sugar, or in bank stock.
To consider attentively; as, to speculate the nature of a thing.
I think science fiction helps us think about possibilities, to speculate - it helps us look at our society from a different perspective. It lets us look at our mores, using science as the backdrop, as the game changer. Mae Jemison
God created the world; the laws of nature were created by God. True science tries to find out what God put in the world. The trouble is where scientists speculate about theology and they don't know what they're talking about because they weren't there. They can't speculate about the origins of life because they weren't there. Pat Robertson
I have a novel that I can write. It's about three soldiers from Somalia. Some babies have been disappearing up on 144th Street, and I speculate later on what happened to them and how they might have been got back. These guys are dead, all three, and they have a chance in the afterlife to do something they should have done when they were alive. Gil Scott-Heron