He defined intelligence as "the ability to carry on abstract thinking".

The emerging discipline is still uncertain of even how to define intelligence.

There are several ways to more specifically define intelligence.

They may not be intelligent in the way we define intelligence, not as individuals, anyway.

Humans have done more than any other species to modify their environment, but is that how we want to define intelligence?

Others think common sense, problem solving abilities and "street smarts" define intelligence.

In doing so the first problem is defining intelligence.

"One might almost define intelligence as the level at which an aware organism demands, 'What's in it for me?' "

The first step to answering the question is to clearly define "intelligence."

They didn't seem to be intelligent, Kim thought, if you defined intelligence as tool-using.