They at once drag in the mind and talk of entities in the mind or out of the mind as the case may be.

For natural philosophy everything perceived is in nature.

We may not pick and choose.

For us the red glow of the sunset should be as much part of nature as are the molecules and electric waves by which men of science would explain the phenomenon.

It is for natural philosophy to analyse how these various elements of nature are connected.
In making this demand I conceive myself as adopting our immediate instinctive attitude towards perceptual knowledge which is only abandoned under the influence of theory.