The object of investigation in this essay is the epic novel sequence Jernbanan written by Sara Lidman. More specifically the investigation takes on the idea of a “sam-vett” as it is formulated in Jernbanan. The “sam-vett” is an idea about the undivided unity of man, nature and animal, and with a kind of primitive trait. By asking the question what traces the history of ideas are to be found in the “sam-vett”, the hope is that it will bring some clarity to the notion and what its message might be. In addition to that a thesis is formulated, that the “sam-vett” can be read as a form of deep ecology. Deep ecology takes on the first rule of ecology, that everything is closely bound together, and extends it to a philosophy. By discussing the notion of the “sam-vett” in the light of two figures in the history of ideas, Jean-Jacques Rousseau and Martin Heidegger, the hope is to unravel its learning. In the end the “sam-vett” can be described as knowledge of nature that is based on a feeling more than the intellect – that begins where the language ends.