On teleology in science.

Defining the “Science of Purpose”

Stephen J. Iacoboni 

Editor’s note: We are delighted to welcome Dr. Iacobini as a new contributor to Evolution News. 

Does the idea of “purpose” have a place in science? Can there really be a science of “purpose”? Has anyone previously tried to describe such a concept? And what might that entail? 

Since the subject matter itself is at the very least novel in the scientific context, questions like these are unavoidable. The “science of purpose” is new to the analytic framework, and is thus obliged to make the case for its claim to validity. 

Purpose in a Framework 

Let’s agree to accept an inarguable definition of science, and see if purpose can be accommodated within that framework. Here is a straightforward and broadly accepted definition of science. It is “the observation of natural phenomena in order to discern recognizable patterns that can be described in a cause/effect relationship, so that a model of that relationship can be developed that provides at the very least a qualitative generalization that applies to those observed natural phenomena. At the quantitative level, such a generalization must be tested to make verifiable predictions regarding the behavior of such phenomena.”

I don’t think that one can easily find an exception to this definition. Science, especially biology, has historically been a descriptive, qualitative exercise. Almost all of the “laws of science,” which apply to the quantitative portion of the definition, are limited to the realm of chemistry and physics. 

The science of purpose can be readily subsumed within the qualitative/descriptive definition. But beyond that, a modeling relation allows for quantitative analysis as well.

Let’s continue with a further definition. What is purpose? I define it as: “the achievement of a predetermined outcome to fulfill a desired goal.” Notice that this definition entails two concepts rarely employed in science: intentionality and the future tense. 

An Endless List 

Yet, with just a little reflection, one realizes that it is straightforward to compile an endless list of examples in nature that exhibit purpose. Bees gather honey, birds build nests for their young, salmon migrate to feed and mate, snakes lay in ambush for their prey, plant stems bend toward the light, gymnosperms spray pollen to reproduce, prairie dogs dig burrows to hide from predators, wolves hunt in packs to improve their predatory success, ruminants travel in herds to resist predation. That would be the taxonomy of purpose, understood in much the same way that anatomists began to understand physiology two centuries ago. 

It was the discovery of the similarity of the anatomy between different classes and phyla of organisms that allowed for biology as a descriptive and qualitative science to progress. In much the same way, one quickly realizes the unity of several discrete purposes that govern and unify the biosphere.

Those purposes include procurement of food, shelter, a suitable environment, mating, protection of offspring, and more. These are all readily definable purposes that define almost all of biota. Purpose at these descriptive levels is undeniable, demonstrable, and easily contained within a generalizable model of organism. Yes, in short, purpose has a place in science.