Ulanowicz on thermodynamics as phenomenology

by Sebastian Benthall

I’ve finally worked my way back to Ulanowicz, whose work so intrigued me when I first encountered it over four years ago. Reading a few of his papers on theoretical ecology gave the impression that he is both a serious scientist and onto something profound. Now I’m reading Growth and Development: Ecosystems Phenomenology (1986), which looked to be the most straightforwardly mathematical introduction to his theory of ecosystem ascendancy, which is his theory of how ecosystems can grow and develop over time.

I am eager to get to the hard stuff, where he cashes out the theory in terms of matrix multiplication representing networks of energy flows. I see several parallels to my own work and I’m hoping there are hints in here about how I can best proceed.

But first I must note a few interesting ways in which Ulanowicz positions his argument.

One important one is that he uses the word “phenomenology” in the title and in the opening argument about the nature of thermodynamics. Thermodynamics, he argues, is unlike many other more reductionist parts of physics because it draws general statistical laws on microscopically observed systems which can be reduced to many different configurations of microphenomena. This gives it both a kind of empirical weakness compared to the lower-level laws; nevertheless there is a compelling universality to its descriptive power that informs the application of so many other more specialized sciences.

This resonates with many of the themes I’ve been exploring through my graduate study. Ulanowicz never cites Francisco Varela though the latter is almost a contemporary and similarly interested in combining principles of cybernetics with the life sciences (in Varela’s case, biology). Both Ulanowicz and Varela come to conclusions about the phenomenological nature of the life sciences which are unusual in the hard sciences.

Naturally, the case has been made that the social sciences are phenomenological as well, though generally these claims are made without a hope of making a phenomenological social science as empirically rigorous as ecology, let alone biology. Nevertheless Ulanowicz does hint, as does Varela, at the possibility of extending his models to social systems.

This is of course fascinating given the difficult problem of the “macro-micro link” (see Sawyer). Ecosystem size and the properties Ulanowicz derives about them are “emergent” properties of an ecosystem; his theory is I gather an attempt at a universal description of how these properties emerge.

Somehow, Ulanowicz manages to take on these problems without ever invoking the murky language of “complex adaptive systems”. This is, I suspect, a huge benefit to his work as he seems to write strictly as a scientist and does not mystify things by using undefined language of ‘complexity’.

It is a deeper technical dive than I’ve been used to for some time, but I’m very gratefully in a more technical academic milieu now than I’ve been in for several years. More soon.


Ulanowicz, Robert E. “Growth and development: A phenomenological perspective.” (1986).