I am reading 'Memories, Dreams, Reflections' by C.G. Jung at the moment. One of his early childhood memories is having made a little wooden figure with a stone. He calls this a first attempt to give shape to a secret.
I can really relate to this. When I am making a sculpture I feel I am giving shape to an idea. The 3D form can express concepts succinctly where mere words would fail to convey them. The idea becomes manifest.