What is the Source of Likeness?

In the previous chapter we attempted to convince the reader that horizontal communication constitutes the background for a coherent whole called the planetary organism. Nonetheless, it does not make sense to talk about a planetary network of living beings without taking a closer look on their individuality. Here we shall deal with a selfhood of individualized organisms, species, and lineages. We encounter the problem especially through the concept of homology, which points towards qualities shared amongst groups of organism as well as to the features that characterizes groups. We enter the area of some 250 years of intensive research during which reputable schools have risen and fallen, and endless battles – often furious – have been fought (sometimes ridiculous ones – and not just from our Whig perspective). The central question behind such a long-lasting intellectual surge is ostensibly simple: why do organisms share corresponding body parts?

[I]t was believed – and in part is still believed today – that we can build up the organism through recourse to its elementary constituents without first having grasped its building plan, i.e. the essence of organism, in its fundamental structure and without keeping this structure in view as that which guides the construction. [ … ] And yet it is a fundamental deception to believe that the effective power behind the transformation of contemporary biology is a matter of newly discovered facts. Fundamentally and primarily it is our approach to the question and our way of seeing that has been transformed – and in accordance with this the facts. This transformation of seeing and questioning is always the decisive thing in science. The greatness and vitality of science is revealed in the power of its capacity for such transformation.

Heidegger 1995, 260–261