Question about Charlotte Mason quote

Looking at the sample pages of Journaling A Year In Nature, there is a quote that says, “We were all meant to be naturalists, each in his degree, and it is in excusable to live in a world so full of the marvels of plant and animal life and to care for none of these things.”—Charlotte Mason. So my question is about the word “naturalists”? Is she taking a philosophical approach in that the “idea or belief that only natural (as opposed to supernatural or spiritual) laws and forces operate in the world.” Or is it the the NOUN definition, “an expert in or student of natural history.” Thank you for your help. I’m not too familiar with all of Charlotte Masons ideologies.