Mulla Sadra and the concept of substantial motion. An extension of ideas in Islamic philosophy about gradations of being and the Aristotelian theory of substance and accident, substantial motion was the idea that throughout their existence beings are in constant motion towards - or constantly changing to align themselves to - perfection.
In Sufi metaphysics (as I understand it) that perfect being or mode of being was pure light.
There is an intuitive connection between the idea of substantial motion and the theory of evolution. The multiplicity of living things and their tendency to change over time can be explained through either of those two lenses. To accept both the ontology of substantial motion and the theory of evolution raises two interesting questions. What drives that motion, and what is the perfection towards which living things are driven?
According to the theory of evolution the driver of change among populations of living things is selection pressure. Evolution has its own vocabulary to describe, essentially, gradations of being and substantial motion among living things. The differentiation of living things is speciation. That unfolding of being that is the surfacing of new characteristics within a species is a result of genetic variation.
But it is selection pressure that ultimately decides if a species or a mutation is a more perfect mode of being than those which preceded it. Selection pressure itself changes over time, because rather than a singular force it is more accurate to think of selection pressure as the force exerted on one mode of being by all surrounding modes of being, which of course are themselves in a state of constant substantial motion. These include other organisms and also environmental considerations like geology and climate.
What extinction events illustrate is that a seemingly near-perfect mode of being at one point in time can easily become sub-optimal or worse when the surrounding modes of being drastically change.
An interesting consequence of the view that selection pressure drives substantial motion in living things is that it may no longer be appropriate to say that living things move along a more-or-less fixed path towards a singular perfect mode of being. If we maintain that there is one perfect mode of being towards which all living things strive, are extinction events mere setbacks in that process? Is carcinization evidence that crab is candidate for the perfect mode of being? Why is there yet so much biodiversity with no evidence of a grand scale convergence in physical or genetic characteristics? Perhaps it suggests that the shifting balance between humans and domesticated species vis-a-vis those left in the wild - the overall loss of biodiversity in general - is not a bad thing after all 🤷
If selection pressure instead drives each thing towards its own perfected mode of being, given the diversity of life and that change within species happens over time in response to the environment, perfect being is then being that is in balance with selection pressure; in accord and with all surrounding modes of being; at one with its environment.
The popular conception of evolutionary theory is “survival of the fittest”, and by this it is often meant that populations or individuals within a population who are competitive and ultimately dominant survive; a mode of being that is decidedly not balanced against the world around it. If we accept that characterization we have invited a rather grim view of perfection and its consequences for all other modes of being. Further what we observe of species that are too successful by this standard is that they invite their own ruin, and that the cascade effects of their overexploitation have negative consequences for all modes of being in their vicinity.
In contrast, the altogether more successful mode of being involves cooperation and reciprocity. For a thorough treatment of that subject, I would naturally defer to Pyotr Kropotkin’s Mutual Aid: A Factor of Evolution.