Perhaps in a billion years or so, this world will evolve intelligent, thinking creatures.

All thinking self-aware creatures change, it seems to me.

Why not other kinds of thinking creatures, as well?

Did it even occur to him that the beings, human and otherwise, whom he had so casually condemned to death had been living, thinking creatures?

She was a member of an entire family of living, thinking creatures.

"The next step is to go beyond the species barrier to other species who are sentient and thinking creatures," he said.

"Do you really think intelligent creatures are going to fall for this?"

It's not as though they are truly thinking creatures.

The gods created us thinking creatures; do you suppose they meant woman to be brood animals alone?

Do you think creatures like that would stay on their own planet?