...What is the pattern which connects all the living creatures?
The parts of a crab are connected by various patterns of bilateral symmetry, of serial homology, and so on. Let us call these patterns within the individual growing crab first-order connections. But now we look at crab and lobster and we again find connection by pattern. Call it second-order connection, or phylogenetic homology.
Now we look at man or horse and find that, here again, we can see symmetries and serial homologies. When we look at the tow together, we find the same cross-species sharing of pattern with a difference (phylogenetic homology). And, of course, we also find the same discarding of magnitudes in favor of shapes, patterns, and relations. In other words, as this distribution of formal resemblances is spelled out, it turns out that gross anatomy exhibits three levels or logical types of descriptive propositions:
- The parts of any member of Creatura are to be compared with other parts of the same individual to give first-order connections.
- Crabs are to be compared with lobsters or men with horses to find similar relations between parts (i.e., to give second-order connections).
- The comparison between crabs and lobsters is to be compared with the comparison between man and horse to provide third-order connections.
My central thesis can now be approached in words: The pattern which connects is a metapattern. It is a pattern of patterns. It is that metapattern which defines the vast generalization that, indeed, it is patterns which connect."
Mind and Nature