For Scientific American Science Quickly, I'm Kendra Pier Lewis in for Rachel Feldman.

Over the past three and a half decades, journalist and author Michael Pollan has written about a dozen books, many of which are in some ways a meditation on what it means to be human and how we interact with the natural world.

In his latest book, A World Appears, a Journey into Consciousness, he tackles his subject head on with a deep exploration of what consciousness is or is not.

Siam's associate book's editor, Bree Kane, spoke with him about his new book.

Here is their conversation.

Just to get us going on something really easy, I wanted to ask you, Michael Pollan, are you conscious? Do you know if I'm conscious and are you 100% certain that this microphone is not conscious?

I can't be sure you're conscious. I have to infer that from the evidence that you're the same species as me and our species can be conscious.

And we have something called philosophy of mind, which is an imaginative faculty that allows us to imagine what other people are thinking.

I know I'm conscious. I think that's actually the thing we know with the greatest certainty.

I mean, Descartes told us that 400 years ago.

The only thing we can be sure of is the fact that we exist and we are conscious.

Everything else is an inference.

So I'm inferring your conscious and I'm going to operate on that basis if it's okay.

And then the microphone, the microphone hasn't shown me any evidence of consciousness.

So, I mean, like you're saying, there's only so much evidence to point to for consciousness.

Some of it is kind of just your gut understanding.

And our February cover issue this year was about these 29 different theories of consciousness,

which you've covered is further evidence that

science is really floundering on finding some solid ground on what is consciousness and how can we

provide evidence to prove this, to tackle this subject with science. But your work seems to really

discuss when science and philosophy start rubbing up against each other,

which I think is why you get into some really interesting questions in this book. So I wanted

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