Some Aristotelian Neo-Thomists (E. Feser call them “A-T philosophers”) accuse intelligent design (ID) of being an expression of the modern mechanistic reductionist quantificationist mindset, and of denying an immanent teleology in nature. I would argue that the difference between internal and external teleology shouldn’t divide ID and A-T. ID doesn’t deny immanent teleology in nature, and has no specific commitment to external teleology or mechanistic thinking.
Teleology is synonymous with function, end, purpose, or goal. Design means conceiving hierarchies of functions. Therefore design and teleology are but the two faces of the same coin.
So why can one say with confidence that a living being has internal teleology and a machine has only external teleology? Because the living, manifested beings come from the ontological Being; they are its direct manifestations. Since the Being is the metaphysical Unity without parts, the manifested beings inherit an high essential degree of unity. All their parts cooperate harmoniously to form a true whole. Their principle is neither in one of their parts nor in the sum of all their parts. All their parts are a unity without composition. Given their direct origin and their integration one says that a living being has intrinsic or internal teleology. We could say also that living beings have a priori finality.
Note that the immanent teleology in nature, deriving from the transcendent Unity, and constituting the basis for a design argument, is so pervasive that a traditional dictum grants us that “in any [natural] thing there is a sign that the Being is unique”.
An artifact is made by man, is quite different. Consequently, its rank is very different fom that of a living being. A machine is not a direct manifestation of the Being (the human constructor introduces a hierarchical step in the middle), and the unity of the machine is low. Moreover the material machine is external to its human constructor. Given this situation one says that a machine has only external teleology.
We could say also that machines have an a posteriori finality. The machine parts — considered separately — have no inherent tendency to cooperate. Yes, there is also a sort of principle of unification, the idea in the mind of the human designer, but obviously it is a far lower principle, relative to the absolute Being. “The works of man are imitations of divine prototypes”, as one said.
The natural vs. artificial difference is fundamental because is ontological. By the way, one of its consequences is that in principle no robot will ever compare with a living being. No IDer to my knowledge claims that the living beings are machines. How could we, also considering that their origin is so different?
Also the claim that Aquinas’ and Paley’s views of design are in complete disagreement is not correct. Paley says that if he finds a watch in a ground he infers design. Paley does not say that living beings are machines in essence (that is what Descartes thought).
Analogously, when an IDer notes that some characteristics of organisms can be described by mechanics, informatics, thermodynamics, control theory, etc. he is not saying that organisms are machines. To describe some properties of an entity in mechanical (or more generally in scientific) terms and to say the entity is only a machine are two different things. By way of analogy, if I say that the side view of a 3D pyramid is a triangle, I do not mean that the pyramid is only a triangle.
IDers don’t confuse living beings and machines. ID must be neither redutionistic nor simplistic. To analyze patterns and relations, to consider parts and calculate the probabilities of their aggregations, is to make scientific models and descriptions. They are necessarily defective, but they may nevertheless help human understanding.
IDers do concur with Thomists in affirming that organisms show an internal teleological organization. ID recognizes the supremacy of natural teleology and doesn’t confuse it with the external teleology of machines. Aquinas’ views, properly understood, and ID arguments from design are compatible. Aquinas’ are “metaphysical demonstrations” (as Feser puts it) while ID deals with scientific inferences. Nevertheless both point to a designer of nature.
Neither is ID a form of deism. The Designer need not be anthropomorphic, a watchmaker who constructs a watch with hands and tool, puts it on a shelf, and then goes home. The universe is not at all external to its Designer (it is an effect in principle contained inside its cause). So the relation between the Designer and the universe cannot be seen mechanistically, as the relation between a watchmaker and a watch (external teleology). On the contrary, the universe can be considered as an idea/project in the “mind” of God (internal teleology).
A-T phylosophers affirm that Aquinas’ Fifth Way doesn’t use the concept of complexity, while ID focuses on it. But this is not necessarily a defect in ID, because spectacular complexity points to teleology in a way that communicates with people who are not convinced by Aquinas’ more essential arguments.
It is true, as Scholasticism affirms, that the supreme Esse transcends any multiplicity. But the cosmos is multiplicity, is complexity; otherwise it couldn’t be a cosmos at all. Science is not metaphysics, it is the study of creation, then of multiplicity. ID, as a scientific enterprise, must deal with multiplicity, with parts and relations among parts. That by no means denies the essence of the One, the First Cause of all. That Being is the supreme Essence, but the cosmos is made of essence and substance, quality and quantity. Metaphysics deals with pure essence, but science in general and ID in particular must deal also with quantity.
To answer the question posed by the title, ID is compatible with both kinds of teleology. ID is simply a science-based method for design detection. Signs and patterns of design can be similar between living beings and artificial systems. Information processes in the cell are similar to those in informatics. A submarine sonar works according to the same principles of a bat echometer. Control systems in the nervous apparatus of animals work according to the paradigms of cybernetics, etc.
More, ID is compatible with A-T. In fact I know many Thomists who are also sympathetic to ID. ID gains nothing by rejecting A-T, because it can be a solid philosophical framework for ID. Conversely A-T gains nothing by rejecting ID because it then discards a useful tool in science that can take its place in the hierarchy of knowledge, and help greatly in refuting Darwinism (unfortunately, some Neo-Thomists actually believe that Darwinism is true!).
For this reason I would invite our A-T critics to meet in friendly discussion with IDers, where sure there would be more agreement than disagreement. After all both A-Ts and IDers — as opposed to atheists/Darwinists — believe in “the existence of a divine ordering intelligence”, and that is what matters.