Some things in life we can prove to be true; some things we know to be true; and some things we accept to be true. Things we accept become beliefs. A desideratum is a powerful belief, a tool by which we guide our passage through life. When difficult decisions must be made after all facts have been assessed, the desiderata of our lives guide how we proceed. Naturalists cope with the interface between humanity and nature, a confrontation sometimes elegant, sometimes hostile. These are a naturalist's desiderata, the tools by which humanity can survive nature and nature can survive humanity. Series presented by Kevin Cook. Desideratum 5: From countless sources we learn of nutrients our bodies need, such as vitamins and proteins. But our minds and spirits require nutrients, too, knowledge and beliefs which are nutrients no grocery store or pharmacy can provide. This becomes the naturalist's quest: grow what enriches you.