Of Thick Trees and Morality: An Analogy.

Envision in your mind an enormous tree containing many limbs, which branch off into smaller branches, which branch off into twigs, which sprout leaves. The branches and foliage are so thick that you can’t see the  trunk of the tree at all.

Alexandre Calame, Landscape with Oak (1859)

Although you can’t see the trunk, you can see the leaves. And you can see that they depend (for their existence and for their sustenance) upon the twigs, and that the twigs depend in turn upon the branches, which depend upon the limbs. From this, it seems to me that there are three basic conclusions you could draw: (a) the limbs are ultimately dependent upon something self-sustaining to sustain them; (b) the limbs are suspended in midair, relying upon nothing else; or (c) the limbs are dependent upon an infinite regress of other limbs, branches, etc., and that there’s no bottom to this series.

Of these three, (b) seems to just wave away the phenomena, treating levitating branches as a brute fact, and (c) violates the rules of logic.So it seems to me that the best explanation would be to conclude to the existence of a trunk, or something like it. And this is so even though the trunk isn’t directly observed. You can demonstrate its existence from its effects.

This is roughly analogous to the situation with the moral law. We see certain things that are morally true because of other, more fundamental truths; these truths are grounded in yet more fundamental truths, etc. Either this chain terminates in maximal truth (which we call God), or it arbitrarily stops, or it regresses infinitely.

This also works as an analogy to teleology: all moral actions are for the sake of some purpose (and “end”), or our action is pointless. But we can drive down deeper: we pursue this end for the sake of some further purpose, or it’s a pointless end to pursue. And this goes on, until we either (a) arrive at a single final end; (b) arbitrarily stop [in which case, the whole chain is pointless], or (c) infinitely regress [which is logically impossible].

If (a) is true, we’re grounding morality in a single final end, which we call God. If (b) is true, then morality is ultimately pointless.


  1. When your debate is complete, we need a whole post dedicated to why infinite regress is a logical impossibility. Intuitively I get it, but not via induction or deduction .

    1. That’s a good question, Daniel.

      As far as I understand it, the key is the difference between per se and per accidens causal series. The latter can have an infinite regress; the former cannot. Per se, or essential, causal series cannot go on to infinity because each cause in the series is instrumental, or derives its causal power from a primary/first cause. Aquinas has the illustration of the stone being moved by the stick, which is being moved by the hand. The stone and the stick are moving (and can only move at all) insofar as the hand is causing them to. They play a role in the series, but only instrumentally; thus, if there is no first/primary cause, the instrumental causes cannot perform at all.

  2. Objectivity by definition precludes drawing any conclusion beyond the leaves, twigs, branches and limbs. Objectively we can all agree on those things. We can reason or logically conclude the likelihood of a trunk, but continuation on the same train of thought would not allow us to conclude roots as they do not logically follow the pattern of observed changes . We would draw a wrong conclusion.

    1. I believe you’ve pointed to where the analogy breaks down, but not where the argument does. If we’re talking about the existence of God, we can refer to the trunk as the culmination of the series (for the sake of illustration). It’s true that a tree requires roots etc., because it is contingent. But that’s precisely where it is unlike God because He is necessary and not dependent on anything else for existence.

      I might also suggest that the rules and laws of logic are objective, but not empirically so; just as we can agree that objectively something either exists or it doesn’t (i.e. principle of non-contradiction).

    2. God creates ex nihilo, and is the cause of His own existence. By definition, there can’t be a second self-caused Cause that creates ex nihilo, so all analogies will wilt a bit.



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