Alexander Pruss's Blog

• Permanence and meaning 2025-10-27
  Consider this strong meaning-permanence thesis: There being a permanent end to all humanly relevant events would render all of our present activities meaningless. And this weak one: There being a permanent end to all humanly relevant events would render some of our present activities meaningless. Here is a quick and easy argument that both are […]
• Spatiality and temporality 2025-10-25
  Here’s an interesting thing: Learning that our spatiality is an illusion need not radically change the pattern of our rational lives. Learning that our temporality is an illusion would necessarily radically change the pattern of our rational lives. To see that (1) is true, note that finding out that Berkeley’s idealism is true need not […]
• Aristotle on flourishing 2025-10-25
  Aristotle thinks that the flourishing of a kind of organism is primarily defined by the excellent exercise of the distinctive functions of the kind. This works great for us: our flourishing is primarily given by the excellent exercise of rationality. But it doesn’t, I think, work well for other organisms. Think of cats and bears. […]
• An argument for the three-species view 2025-10-23
  Some contemporary Thomists have the idea that there are exactly three metaphysical species—three kinds differentiated by qualitatively different natures—of living things: plants (maybe broadly understood as non-sentient living things), mere animals, and rational animals. Here’s a line of thought that yields two-thirds of the view, starting with a premise that most medieval Aristotelians would have […]
• Divine timelessness and the A-theory of time 2025-10-22
  One can only know a proposition when it is true. One can only know a proposition when one exists. Thus, one can only know a proposition if it ever happens that one exists while it is true. (1 and 2) If the A-theory of time is true, the proposition that it is a Wednesday is […]
• Probably most people you know are more social than you 2025-10-22
  You might observe: Most of the people I know are more social than me. And then you might beat up on yourself, concluding: I am less social than most people. But the inference from (1) to (2) is obviously fallacious. For whether you know a person is a function of how social you are and […]
• Another infinite dice game 2025-10-21
  Suppose infinitely many people independently roll a fair die. Before they get to see the result, they will need to guess whether the die shows a six or a non-six. If they guess right, they get a cookie; if they guess wrong, an electric shock. But here’s another part of the story. An angel has […]
• Theism and presentism 2025-10-18
  Suppose presentism is true and truths about other times are grounded in tensed facts, such as the fact that there were once dinosaurs. Given presentism and theism, God is in time. Suppose, as the Abrahamic religions hold, that God created all contingent things a finite amount of time ago. Before God created them, it was […]
• Growing Block and a time bias 2025-10-15
  Here’s a curious argument against Growing Block. Other things being equal, it is better to receive goods earlier in life and to receive bads later in life if Growing Block theory is true. For the earlier you receive X in life, the larger the portion of your life during which X is a part of […]
• Two kinds of time bias 2025-10-15
  In our philosophy of time seminar, we have been thinking about time biases. Humans appear to discount future goods and bads so that a good or bad with value λ at temporal distance T in the future has effective value f(T)λ for some monotonically non-increasing function f. We might call this a relational time bias—the […]
• What is real change? 2025-10-15
  I am starting to think that it’s rather mysterious what real change—i.e., non-Cambridge change—is. (Cambridge change is illustrated by examples like: Alice became shorter than her son Bob because Bob grew.) It is tempting to say: x undergoes non-Cambridge change if and only if there is an intrinsic property that x gains or loses. But […]
• A compositional fine-tuning argument 2025-10-15
  Assume naturalism about the human mind. Our best naturalistic account of the human mind is functionalism. But functionalism faces multiple too-many-minds problems. The most famous of these are the Chinese Room and its variants like Schwitzgebel’s consciousness of the United States argument. But a more troubling bevy of problems comes from abundant ontologies. Thus, as […]
• Avoiding temporal parts of elementary particles 2025-10-14
  It would be appealing to be able to hold on to all of the following: Four-dimensionalism. Elementary particles are simples. There is only kind of parthood and it is timeless parthood. Uniqueness of fusions: a plurality of parts composes at most one thing. But (1)–(4) have a problem in cases where one object is transformed […]
• Aristotelianism and fundamental particles 2025-10-10
  A number of contemporary Aristotelians hold to the view that when a fundamental particle becomes or ceases to be a part of an organism, the particle perishes and is replaced by another. The reasoning is that the identity of parts comes from the whole substance, so parts are tied to their substances. I’ve long inclined […]
• Beyond persons? 2025-10-09
  I wonder if creation includes beings that are qualitatively as high above mere persons like us as mere persons are qualitatively above non-persons. Persons have agency and intellectuality (let’s say) and that gives them a dignity above non-persons. Is there some quality Q that is even more impressive than agency and intellectuality and that is […]
• Two kinds of change 2025-10-08
  I ran across this old post of mine and it made me think that there is an interesting distinction between two kinds of change which one might label as objectual and factual change. Objectual change is change in objects, including both an object’s acquiring or losing properties and an object’s coming or ceasing to be. […]
• Mononoetism 2025-10-07
  Every so often I come against someone who is defending a Christological view I want to call “mononoetism”: that Christ has only one mind. While the Third Council of Constantinople condemned the errors that Christ has only one will (monothelitism) or only one natural operation (monoenergism), I do not know of any conciliar condemnation of […]
• Octopuses, aliens, squirrels and AI 2025-10-07
  I’ve been toying with an argument for dualism along these lines: Octopuses are conscious. Technologically advanced aliens are or would be conscious. Squirrels are conscious. Current LLMs are not conscious. Claims 1–3 require a pretty strong multiple realizability. On materialism, our best such multiple realizability is a functionalism. But it is likely that our current […]
• A Stoic thesis 2025-10-02
  Combine these two rather Stoic theses: No one can make the fully virtuous person worse off Doing what is morally wrong always makes you worse off and you get: No one can make the fully virtuous person do what is morally wrong. It is going to be crucial to this post that (3) includes cases […]
• Existing and existing at a time 2025-10-01
  If we accept growing block or eternalism as our theory of temporal reality, we have to make a distinction between existing simpliciter (i.e., being in the domain of unrestricted quantifiers) and existing-at-a-time (including tensed existence at the present). To exist at time t is not the same as its being the case at t that […]