The Greek philosopher Anaximander (610–546 B.C.E.) speculated—correctly—that air wasn’t just nothing, but, in fact, was made of something. However, he went on to suggest that all matter came from air, which could be changed into different states of matter. This idea actually has some basis in truth, since, for example, water can be precipitated out of humid air, and water can evaporate into air. Anaximander just got a little too carried away and took this idea to extremes by saying air could also become fire and a lot of other things.