A Treatise of Human Nature taste to be in the other), arguing that unextended perceptions must somehow exist without having a location. But the contrary problem arises for dualists: how can extended perceptions (of extended objects) possibly be conjoined to a simple substance? Indeed, Hume waggishly adds, this is basically the same problem that theologians commonly press against Spinoza's naturalistic metaphysics: thus if the theologians manage to solve the problem of extended perceptions belonging to a simple substance, then they give "that famous atheist" Spinoza a solution to the problem of extended objects as modes of a simple substance. Finally, Hume examines "causal relations", arguing
Chemistry: A Volatile History unimportant parts, primarily water, Brand boiled the urine for several days until he was left with a thick paste. Finally, fragments of a substance emerged which burned brighter than any Medieval candle available at the time, but which left the vessel it burnt in cold: Brand named this new substance icy noctiluca – ‘cold night light’. Soon after its discovery, icy noctiluca toured the Royal Houses of Europe and in 1677 it came before the Royal Society in London, then under the chairmanship of Charles II, where one of its members decided to investigate. In his book "New Experiments and