(I) For a long time, science was more or less a united whole known as “natural philosophy,” and wasn't that far removed from art. (II) Then, in the 18th century, the distinctions between the scientific fields began to appear. (III) Later, in the 19th century, to take two examples, physics and chemistry went their separate ways. (IV) Actually, several physicists in the 1930s and 1940s tried to apply their knowledge to microbiology. (V) So, the sharp border that we now see between the arts and sciences is but only a few centuries old.