Why did empedocles(philosopher) include earth in the four primordial elements?

Question

why earth?

please explain.. thank you

Answer 1

earth = mineral such as iron that organism need.

Answer 2

Though it would be nice to think that he had intuited the four states of matter that are still recognized today (solid, liquid, gas, plasma), judging from his discriptions of the elements it is probably more accurate to say that he wanted to have two sets of paired dualities (or three, if you include the motive forces of love and strife).

Earth, in that sense, is opposed to air.  Deep in the earth there is no air, and up in the air there is no earth.  At least in amounts measureable to the Greeks.  It would be natural to think of them as opposed - where there is one, there is not the other.

Or perhaps he chose earth simply because of horticulture.  He uses many plant analogies in his work, and refers to the elements as 'roots'.  As such, if you want to grow a plant, you need soil, water, air, and light.  Your classic four elements, more or less.

I suppose only Empedocles himself could tell you why he chose those specific four.  There were certainly other contemporaries who made many different choices themselves, and without much better apparent reason.  Hope that helps!