When and how was the water cycle discovered? Did people, like ancient Greek philosophers, have any correct ideas on the water cycle? Was its discovery more of a recent thing?
In Aristotles Meteorology, we have:
Now, the sun, moving as it does, sets up processes of change and becoming and decay, and by it's agency the finest and the sweetest water is carried up and is dissolved into vapour and rises to the upper region, where it is condensed again by the cold and so returns the earth.
And he notes this again in his Physics that:
Zeus does not send the rain in order to make the corn grow: it comes of neccessity. The stuff which has been drawn up is bound to cool, and having cooled, turns to water and comes down. It is merely concurrent that this having happened, the corn grows.
Hence, the hydrological or water cycle, at least in Europe, was known by Aristotles time, and so by 350 BCE.