I don't think of sculpture as languge, but as a man-made object which arrests us. It births as experience which interrupts thought by evoking feeling. Only later do we explain this experience, now a memory, by language.
Let me respond instead to Brancusi saying, "What is real is not the external form, but the essence of things....it is impossible for anyone to express anything essentially real by imitating its exterior surface." Or Degas saying, "The object of art is not to reproduce reality, but to create a reality of the same intensity" For me, sculpture isn't separate from any other art form or means of expression. It is a way of creating a new separate reality, which is at its core the same reality.