Both (separately though, the two answers are not related even though I put them in one post - I'm allowed to have more than one thought about something).
We just don't understand intelligence (not the brain, intelligence) well enough to duplicate it, never mind improve it.
And I don't think we ever will because to understand something complex you have to be more complex than that thing, but by definition we can not be more complex than ourself - so understanding our own intelligence will always be beyond us.
That's the objective part.
The subjective part is that I personally believe that intelligence is not physical. The brain mediates it, but the source is elsewhere.
The soul maybe, or that we are really game characters in an MMOG.
We just don't understand intelligence (not the brain, intelligence) well enough to duplicate it, never mind improve it.
And I don't think we ever will because to understand something complex you have to be more complex than that thing, but by definition we can not be more complex than ourself - so understanding our own intelligence will always be beyond us.
That's the objective part.
The subjective part is that I personally believe that intelligence is not physical. The brain mediates it, but the source is elsewhere.
The soul maybe, or that we are really game characters in an MMOG.