Thoughts on the Paradox of Theseus

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A thought experiment can provide the impetus to the formation of a theoretical apparatus applicable in the discernment of sense-impressions or, conversely, reveal an analytical system already in operation.

Metaphysical notions, preconceived or not, largely determine the parsing of information about states of affairs. Recognising, scrutinising and revising such notions can thus bring about a shift in the overall appreciation or comprehension of actual and possible facts.

The perception of change on ontic objects relative to the significations attached to them or the reassignment of meaning on ontic objects that hold constant relative to themselves, is a binary of cases indicative of such workings.

The Paradox

To elaborate on this claim, we shall tackle the problem of signifying a composite object whose original parts have been fully replaced by newer ones. This is an age-old mental exercise, known as Theseus’ Paradox. As Plutarch puts it in his Theseus:

The ship wherein Theseus and the youth of Athens returned had thirty oars, and was preserved by the Athenians down even to the time of Demetrius Phalereus, for they took away the old planks as they decayed, putting in new and stronger timber in their place, insomuch that this ship became a standing example among the philosophers, for the logical question of things that grow; one side holding that the ship remained the same, and the other contending that it was not the same.

Is the ship the same or not? We begin by noting the distinction between ontic and noetic objects (see the recent posts for details, such as this); a metaphysical bifurcation which indicates that we are not examining change or lack thereof of the ship as such, but rather of the ship qua object of sense in tandem with the ship qua object of thought.

It is stated that work was done to substitute the ship’s older parts with newer ones. To argue that, in material terms, there has been no change whatsoever would require us to deny the very fact of the labour involved and to oppose our basic intuition of experience in discerning decayed from strong timber, work at the docks from idleness or unemployment etc. Taken to its logical end, it would have us refuse to accept as case-specific valid information the solidity of rock, the liquidity of water, our planet’s gravity and so on to the point where our very interaction with all that is susceptible to the faculties of sense would be held as either outright illusory or largely insufficient for grounding an adequate understanding of things.

Pure reason could be juxtaposed to experience as the sole reliable instrument available to human, as only it could, purportedly, strip away all phenomenal superficialities to grasp the ‘essence’ of things. While valuable and worth pursuing for the sake of validating/falsifying it conclusively, this approach seems to leave something to be desired, at least prima facie. Mundane as it is, the very possibility of death from a fall to the ground — courtesy of there being ‘ground’ and the force of ‘gravity’ — that would result in the terminal inability of one to resort to reason, should have us question the commitment to pure reason as the sole reliable criterion for acquaintance with the world.

Instead of propounding such arguments against testable experience, we make sufficient empirical evidence the midpoint of our research of change in the ship’s components.

We do, however, have to take it a step further. The information received by the senses is not enough to answer satisfactorily the logical problem now examined, for it remains to be seen whether the idea of the ship, the noetic object in question, has been affected by any material alterations to its corresponding ontic presence.

Here the issue is broadly divided in three parts where (i) the noetic object has changed since we incorporate such meanings as ‘renewed’, ‘remodelled’ etc. to the general signification Theseus’ ship, (ii) we have no means of verifying Plutarch’s account on the ship and cannot recognise any modification made to it, thus opting to hold the notion constant in correspondence with [what appears to be] the unchanged ship qua object of sense, or (iii) we uphold that the signification has not changed whatsoever in spite of providing assent to Plutarch’s description, for we still consider Theseus’ ship equal to itself, as transcending the spatiotemporal mechanics of change determining its actuality.

Discussed in further detail, these give us the following:

  1. In the first case, the main element is that of ‘awareness’, viz. that we are informed of the alterations to the ship’s constitution and, consequently, we modify our notional understanding of it to account for that new data, in an effort to achieve epistemic correspondence between thing and thought.

  2. But what if we were to remain oblivious to the facts Plutarch describes and/or these were not identifiable/verifiable upon inspection? Would the signification [have to] be reformulated? If correspondence were the sole determining factor and if no alteration to our perception of the ship qua ontic object’s constancy were to be made, then the answer would have to be firmly negative.

  3. Which brings us to the third scenario of holding the signification constant in spite of having full awareness of the material change(s). To place further emphasis on this point we may fathom the reversal of Theseus’ paradox, a situation where the ship qua object of sense remains constant — with us having full awareness of it — while the ship qua object of thought undergoes change. No quantum of timber is touched, just the meaning of Theseus’ ship, i.e. the signification attached to the physical object, is being altered. A transfer of ownership from, say, Theseus to Jocelyn would have us adopt the meaning to denote the change from Theseus’ ship to Jocelyn’s ship in full knowledge of there being a single, constant, persistent physical object that is referenced.

Concluding remarks

The afore-enumerated cases reveal a certain disconnect between ontic and noetic objects in terms of their interplay. The change or constancy of one does not necessarily result in the change or constancy of the other.

While epistemic correspondence is essential to inquiry, it is not brought about mechanically or independent from a conscious method and commitment to the concentration, arrangement, concatenation, discernment and clarification of the data that forms our [given] knowledge.

The gist is that a certain metaphysics, such as the conception of thought and thing as a singularity, will engender an understanding of the world that differs profoundly from the one that is informed by the bimagnitudinal metaphysics here considered.

In this regard, the philosophical controversy Plutarch alludes to perhaps stems from a common approach to metaphysics among the competing views: a monolithic worldview that, essentially, does not account for the peculiar relation between the ontic and the noetic.

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Protesilaos Stavrou

EU policy analyst. Philosopher. Web developer.
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