I prefer the term physicalist to the term naturalist. But then, I study physics.
The difficulty is that atheism doesn't imply physicalism, nor does the reverse implication hold (I have met physicalist theists--they just think deities are physical).
So, atheism is simply not having a belief in any deity.
Physicalism is thinking that everything is, ultimately, physical (and subject to natural laws).
And ethically, I am a Secular Humanist.
None of these positions implies any of the others.
The difficulty is that atheism doesn't imply physicalism, nor does the reverse implication hold (I have met physicalist theists--they just think deities are physical).
So, atheism is simply not having a belief in any deity.
Physicalism is thinking that everything is, ultimately, physical (and subject to natural laws).
And ethically, I am a Secular Humanist.
None of these positions implies any of the others.