Catholic Metaphysics (Thomism)

I subscribe to classical theism  (vs  personalist neotheism) with scholastic Aristotelian-Thomist metaphysics (hylemorphism and essentialism), and natural law theory as ethics.

This worldview implies that I endorse the following (often hardcore common sense) notions that mostly would have to be denied by a consistent materialism and naturalism (compare Alexander Rosenberg's book "An Atheist's Guide to Reality"):

  • objective truth exists, based on a correspondence theory of truth
  • external reality exists (objective realism) and counterfactual definiteness (but not locality) holds (contra the Many Worlds Interpretation of quantum mechanics). I concur with the direct realism of Aquinas that we perceive objects as they really are (there is no difference between primary and secondary qualities).
  • a unified and enduring self exists, based on the neo-Aristotelian hylemorphic view of the soul as substantial form of the body
  • a soul exists and mind-body dualism is true, but with fundamental unity of body and soul (hylemorphic dualism, not Cartesian dualism!)
  • phenomenal consciousness (qualia) exists (contra the views of eliminative materialists like Daniel Dennett), but it has material aspects because it is spatiotemporally located.
  • intentionality (aboutness) and rationality are not illusions, and require the real existence and causal efficacy of propositions. However, it is not words that possess a queer property of intentionality, but only persons are intentional and use words for this purpose.
  • ontological pluralism: ontological and numerical distinctness of subjects from objects and between subjects (contra Eastern non-dualism and monism)
  • genuine free will exists, based on mental/agent causation (only coherent with hylemorphism and classical theism).
  • objective moral values (moral realism, grounded in divine nature and natural law) and moral obligations (grounded in divine will) do exist (deontological ethics and natural law theory, rather than a voluntarist divine command theory sensu Ockham)
  • moral responsibility and retributive justice, grounded in the reality of enduring selfs, genuine free will, and objective moral values and duties
  • an A-theory theory of time (sensu McTaggart), but without viewing time as real thing (i.e. an empty container for events) in itself, but just as a measure of change. Time does not exist without events and without change. There is real temporal becoming with a determined past and a moving now that advances into an indeterminate future (theistic presentism, with God's omniscient knowledge as truth maker for past and future events). Since change is always local, Thomism can affirm a kind of point presentism that does not require a global now as preferred reference frame and thus does not conflict with special relativity.
  • endurantism as theory of persistence, with essentialism as explanation for diachronic identity
  • genuine causality with all four Aristotelian causes and a notion of causal powers that bring about effects based on immanent teleology
  • indeterminism (neither quantum events nor free will decisions of embodied agents are determined by any temporally prior conditions, but they are atemporally preordained by God). Fatalism is wrong, because all actions matter.
  • there is genuine teleology, purpose, and meaning of life and the universe
  • moderate/scholastic realism (theistic conceptual realism) of abstract objects and universals (as thoughts in the mind of God)
  • actualism (not possibilism) as metaphysics of modality (modal realism is wrong), based on Aristotelian-Thomist hylemorphism. Modality is based on actual reality, not the other way round (I reject modal logic and its possible world semantics).
  • a propensity view of probability that locates probabilities as objectively inherent properties of substances and their (Aristotelian) potentiality.
  • composite objects (substances) really exist and have substantial forms (mereological realism instead of mereological nihilism/universalism/essentialism), thus I reject atomism as metaphysically fundamental.
  • a moderate version of the principle of sufficient reason (PSR), which requires explanations for the existence of all things/substances and all facts (and thus a necessarily existing atemporal God as ultimate source of all temporal and contingent existence and order), but not necessarily requiring contrastive explanations (why this state of affairs rather than another).

As committed Christian theist I reject the incoherent world view of naturalism, which necessarily implies atheistic materialism and scientism and thus automatically leads to nihilism.


As Aristotelian-Thomist thinker I subscribe to a reductionist or relational view of time (change is fundamental) and space (contra the substantival view of the Minkowski spacetime block universe), a neo-Lorentzian interpretation of special relativity, an Aristotelian-Thomist interpretation (sensu Wolfgang Smith) of quantum mechanics, and possibly a canonical quantum gravity with fixed foliation. I support the Aristotelian view of immanent teleology pervading all of nature, and thus reject purely mechanistic explanations of biological complexity and diversity. However, unlike some Thomist philosophers (e.g., Edward Feser) I reject the deistic notion of "Theistic Evolution" (sensu BioLogos) and endorse the necessity of divine intervention (infusion of information) in the origin and history of life. I agree with Chaberek (2017) that Thomist metaphysics is incompatible with Neo-Darwinian unguided macro-evolution, but well compatible with intelligent design theory.


What about alternative world views?

During my nearly 15 years of intensive studies of metaphysics and philosophy, I thoroughly evaluated very different alternative world views like atheistic materialism (naturalism), Eastern non-dualism, Integral Thought, quantum mysticism, process philosophy, objective idealism, neoplatonism, mathematical monism, and deism. I studied most of the pro and con arguments, and ultimately came to the conclusion that there are only three serious and potentially viable alternatives to  a theistic world view:

  • Max Tegmark's mathematical monism ("Our Mathematical Universe") is the only version of naturalism that could explain the fundamental questions, why there is something rather than nothing, why there are laws of nature and causal relations that generate order in the universe. To be a complete world view, Tegmark's hypothesis would have to be combined with the unrestricted naturalism of Gary Drescher ("Good and Real"), and the extremely nihilistic eliminative materialism of Alexander Rosenberg ("An Atheist's Guide to Reality"), which is the only coherent version of naturalism. Finally, a field-version of Giulio Tononi's Integrated Information Theory of consciousness might complete this world view, as it is the only known putative candidate for a naturalistic explanation of the hard problem of consciousness.
  • John A. Leslie's axiarchic Neoplatonism, sans his gratuitous inflation of the number of divine minds, and instead combined with the objective idealism of Timothy Sprigge.
  • Alfred North Whitehead's panentheistic process philosophy (not its neo-Whiteheadian "reformation" by process theologians like Charles Hartshorne or David Ray Griffin).

However, all three alternatives ultimately involve much more severe problems, absurdities, and incoherences than theistic world view:

  • Tegmark's  original mathematical universe hypothesis implies an infinite world ensemble and is refuted by the measure problem of cosmology, the freak observer problem (Boltzmann brains), the problem of how to derive the Born rule if every outcome has the probability = 1, and the preferred basis problem of the Many Worlds Interpretation, as well as arguably Gödel's incompleteness theorem. These problems can only be partly avoided by a much weaker version, which Tegmark calls Computable Universe Hypothesis CUH. However, the latter comes at the cost of postulating a contingent subset of mathematics as existing, while other parts of mathematics would be non-existent. Such a contingent CUH cannot be considered as necessarily existing, and thus can no longer explain, why there is anything rather than nothing. Furthermore, Tegmark's and Drescher's naturalism ultimately implies absurd metaphysical nihilism, as they suggest that nothing particular exists, but only abstract objects (there is no magical spark of existence that makes some possible worlds really real). Rosenberg's extreme naturalism implies complete nihilism concerning mental phenomena, including the absurd view that nobody really exists (there is no self), nobody ever felt pain (qualia do not exist), and nobody ever thought about anything (there exists neither propositional content nor intentionality/aboutness). Tononi's Integrated Information Theory presupposes consciousness rather than explaining it, because without consciousness there simply is no information to integrate. 
  • Leslie's axiarchic Neoplatonism does neither account for the unified consciousness of the divine mind nor for that of all the finite minds existing within the divine mind, it implies a block-universe view with all its problems, it inherits all problems of Platonism (exemplification tie, third man problem, unintelligibility of moral Platonism), and it suffers from the problem of implied actual infinities (do all digits of Pi exist in the divine mind?). Furthermore, it suffers from the fatal problem, how the proportion of Good and Evil in a particular world should be weighed against each other by an axiarchic principle, and it has no answer to the question, why there should only be a single good axiarchic principle (Plato's form of the Good), rather than multiple conflicting axiarchic principles including evil ones.
  • Finally, every version of Whitehead's process philosophy completely fails to account for why there is anything rather than nothing (Whitehead's postulated basic metaphysical principles would just exist without any explanation), and it implies a bundle view of the self with all its problems and absurd consequences (see here). Furthermore, process philosophy is empirically falsified by modern Big Bang cosmology (esp. Borde-Guth-Vilenkin theorem), as it necessarily presupposes a past-infinite universe (see here).

No world view apart from theism can really account for an enduring and unified self. Thus, if you do believe that YOU exist, than you must accept theism! There is an easy test if you do indeed believe that you exist as an enduring and unified self, even if you are pretending otherwise:

  • Do you think that you are still the same person as the one who began to read this webpage?
  • Would you be  afraid if you would know that you are going to be horribly tortured tomorrow?
  • Would you be afraid to use a hypothetical traveling service, in which all your body matter is scanned and turned into dust, sent in an urn by post to your destination, and there re-assembled (identical down to the quantum level) to a living body?
  • Did you ever really experience pain and suffered?
  • If a mentally healthy, cold-blooded murderer slaughtered your loved ones just for the fun of it, would you hold him morally responsible for his crime and would you want him to be punished (not only to protect others)?
  • Did you ever come to believe something is true because you evaluated the arguments and used you rational faculties to come to the conclusion that this particular belief is rather true than false?

If you answered any of these questions with yes, than you are highly irrational if you still embrace atheism and materialism, because these world views are totally incompatible with the fundamental beliefs you just confirmed.


To sum up: There are no reasonable alternatives to theism, and therefore as rational human one should believe in God.