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 Demetrus 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 as to things that grow; one side holding that the ship remained the same, and the other contending it was not the same.
(Plutarch 1880, 7-8)
Consider this: A wooden ship of old is exalted beyond all other seafaring vessels and the proud townsfolk decide to maintain the ship in the harbour in pristine condition. Every year a plank of wood is replaced. This continues for many long year until every original plank, the rigging and every bronze nail has been supplanted. The ship looks exactly the same as the day it was commissioned, with all pomp and ceremony and much blustering by self important officials culminating with the then incumbent Mayoress, Dame Lilly Magumbo, shattering a bottle of ‘Blue Nun’ on its glistening newly commissioned hull. I’m staring to digress. The ship even displays the same name plate, ‘Salty Ferret’ and conforms to all the original dimensions in every regard. The point is: Although every piece of the original ship has been changed we end up with a structure that looks the same as the original ship and bears the same name. Would you consider this to be the same ship that slid off the slipway all those eons ago?
Consider a second scenario: During the protracted restoration process a long line of boat yard enthusiasts decide to collect all the old pieces of the original ship and lovingly preserve the discarded bits. You know the type. The sort of folk who hang around train stations with a notebook, pencil, single lens reflex camera and a hope in their heart that they will catch a glimpse of the 2.13pm Dudley to Tipton express. Invariably they work as office clerks and share a slovenly house with an elderly widowed mother with a penchant for cats.
Said enthusiasts decide, after a very long collection period, to rebuild the original ship in all its majestic glory. After toil, lovingly given, a new/old ship is completely restored and floats resplendent next to the ‘Salty Ferret’. The enthusiasts ponder mightily, and after much deliberation and consideration, unanimously decide to call the ‘new’ ship, ‘Salty Ferret’. The townsfolk are nonplussed and discombobulated and berate the enthusiasts, thusly: “Hold hard Sir, we already have the original ‘Salty Ferret’ here in the harbour. Tis imperative that you name this impostor ship by another moniker- why not call it ‘Salty Ferret II’. But the upstarts (for it is they) retort: “Surely, our ship is the true ‘Salty Ferret’ as it contains all the original wood and rigging. Your ship, Sir, is the impostor”.
So which ship is the correct ‘Salty Ferret’? Those who hold dear in their heart the version that endured eons of despoliation and repair or those who hold true to the version lavishly constructed from the original material? What we can agree upon is that both ships cannot be the original ‘Salty Ferret’- or can they?
This is not a trivial question as it may first seem. It carries grave metaphysical consequences which have engaged clever minds for well over two thousand years and questions our fundamental conception of what is ‘identity through time'. We know that the human body changes all its cells over a period of approximately seven years. During this time interval our cells are gradually replaced and from the perspective of physical composition we are not the same organism that existed seven years ago, nevertheless we are still considered the same person. In simple terms we consider the object more than the some of the parts. And from this viewpoint both ships can lay legitimate claim to be the original 'Salty Ferret' albeit separated by material and construction. Confusing, ain't it?
Stretching the concept to the human condition, once again: What happens at the time of death? Surely the body is just a vessel and once life has ceased the person no longer remains even though, initially at least, the material composition is virtually identical to the state of life just prior to biological death. Our human existence and identity is clearly more than the accumulation of cells and even biological activity. Does our essence lie exclusively within the neurons and tissue of the brain? Is what makes us an individual- consciousness? What is consciousness anyway and how is it related to the myriad of interconnected neurons and electrical activity? Those of a religious inclination would suggest that continuity is maintained through the conception of the soul. This is, to me, a highly unsatisfactory explanation. And I would argue that it offers no new rational information to an already dense and opaque problem. After all, are we not simply layering an unintelligible concept onto an already complex and obscure problem?
I've strayed from our mythical ship and extended the metaphor into dark, murky philosophical territory. A deceptively simple problem, at least on first appraisal, has become intellectually abstruse and probably unsolvable by mortal minds. Contemplation of this and similar questions deepens our understanding of existence (maybe) even though we seem no closer to any firm and intellectually satisfying solution. All the best questions in life, the ones that enrich our intellectual existence, are invariably elusive and ultimately unanswerable.