In 2012, Google (s goog) hired Ray Kurzweil to build a computer capable of thinking as powerfully as a human. It would require at least one hundred trillion calculations per second — a feat already accomplished by the fastest supercomputers in existence.

The more difficult challenge is creating a computer that has a hierarchy similar to the human brain. At the Google I/O conference Wednesday, Kurzweil described how the brain is made up of a series of increasingly more abstract parts. The most abstract — which allows us to judge if something is good or bad, intelligent or unintelligent — is an area that has been difficult to replicate with a computer. A computer can calculate 10 x 20 or tell the difference between a person and a table, but it can’t judge if a person is kind or mean.

To get there, humans will need to build computers that can…