Stone Tools

~2.5 Million B.C.

Humans are not descended from monkeys. Rather, humans and monkeys share a common evolutionary ancestor. In fact, the further back in time you go, the more common ancestors that humans have with essentially every living organism on the planet. Homo sapiens (humans) only diverged from their most recent ancestor, Homo erectus, about half a million years ago. About 2.5 million years ago, proto-humans began using basic tools made of chipped stone. These tools were much more crude than the intricately carved stone arrowheads or grindstones of more recent stone-tool-making people, but they represent some of humanity's (or proto-humanity's) early ingenuity and thinking.

Our Thoughts...
Thinking played an essential role in our struggle for survival. The way we think--the level of abstraction and complexity that we are capable of--is what makes us unique as a species. Einstein said, "We cannot solve our problems with the same thinking we used when we created them". In this statement, Einstein not only recognizes the importance of thinking to our survival, but also offers a subtle hint about the evolutionary nature of knowledge itself.

Language is the link between individual thought and thinking as a collective. Piaget writes, "Language leads to the socialization of actions, which gives rise to acts of thought no longer exclusively related to the self that engenders them; from now on thought is related to a broader plane of communication. Language is, in effect, the vehicle for concepts and ideas that belong to everyone, and it reinforces individual thinking with a vast system of collective concepts. The child becomes immersed in these concepts as soon as he masters words."