Are you for real?

Reality is a tricky thing to think about.  In philosophy, discussions about reality fall under the sub-discipline of metaphysics.  Like a lot of topics in philosophy, or life for the matter, the more you think about something, the less clear it becomes.  The line between real and unreal can get blurred pretty quickly, and once it’s blurred, I’m not sure there is any coming back.

One of the most noted problems within metaphysics is called the problem of personal identity, i.e. how can I be the same as myself after undergoing some kind of change.  This point has been illustrated by several examples including the storied Ship of Theseus. 

Imagine a ship that is persistently at sea, stopping intermittently in order to restock supplies.  At some point throughout its journey, it’s noticed that one of the boards used to construct this great ship has rotted and needs to be replaced.  The board is easily replaced, and the ship continues to sail.  Eventually another board needs to be replaced, and again the matter is attended to without interruption.  Again, after some more time passes, another rotten plank is observed and is thus replaced.  After an extended yet finite amount of time each board that makes up the Ship of Theseus is replaced, one at a time without ever disrupting the long-lasting journey.

Suppose there are exactly 1,000 boards that make up the ship, and each is replaced at different points along the way, until eventually, each and every plank has been replaced.  

After such an overhaul, is the ship that eventually comes to rest the same ship that initially set sail.  In other words, is the ship that finally docks the Ship of Theseus?

Several iterations of this problem follow, e.g. are you driving the same car that you bought after you change a tire, is your apartment the same place you moved into after hanging a photo, are you wearing the same shirt after it loses a button?

Answers to these questions can be very informative, but things start to get more interesting when we apply similar questions to ourselves.  Are you the same person you were when you were born?  Are you the same person before and after getting a haircut?  Are you the same person who started reading this article just a few minutes ago?

According to the Principle of Indiscernibility of Identicals the answer to each of these questions is a resounding NO!

Principle of Indiscernibility of Identicals: If A = B, then every feature of A must be a feature of B.

The ship doesn’t include the same boards along the journey; therefore, it’s not the same ship.  Your shirt doesn’t contain the same number of buttons; therefore, it’s not the same shirt.  You don’t contain the same cells that you did when you were born; therefore, you aren’t the same person.  Of course, we might say that our DNA is the same, but going down that road is perilous.  If we reduce ourselves to DNA, we will have an incredibly challenging time explaining concepts like memory, laws, ownership, and nearly everything else that we claim as the makeup of our lives.

The pre-Socratic philosopher Heraclitus claimed that “we can’t step into the same river twice”.  Considering the Principle of Indiscernibility of Identicals, he might be right.  For climbers, perhaps claiming that we can’t climb the same route twice will carry more significance.  But whether we are stepping into a river, or climbing up a wall, the point remains.    If we try to repeat a route, that second climb will not be the same.  It may not be immediately visible, but anyone who has ever climbed at a well-visited crag knows all too well how polished the rock can become.  Rock changes!  Rock is always changing; you really can’t go up the same route twice.  Just as important as the rock, is the change happening to us.  Just as the rock becomes polished over time, we too undergo constant change.  Just as the river is always changing, so too are we. A point that may seem innocuous but comes with enormous metaphysical concerns.

Suppose there is a climber who just can’t finish a route, not to suggest that there aren’t other climbers who could finish the route, but this particular climber is just stuck.  Without considering contemporary mores regarding climbing etiquette, our stuck climber decides to break out a hammer and chisel in order to carve a hold into the crux of this route.  He creates a nice jug (deep hand hold), pops on a harness, ties into a rope and completes the route.  As word gets out, the actions of our climber are met with outrage.  The climbing community has a penchant for justice concerning those who go against the ‘Leave No Trace’ mantra.

Outrage turns too demands, and demands turn to Instagram!  Before too long our climber is identified, and an angry mob forms outside his Sprinter Van.  His likeness burned in effigy.  Climbers mandate compensation from the vandal, no less than a pound of flesh for his transgression.  As the mob expands and the chants get louder, a climber emerges from the Sprinter Van.

There is a hush upon the horde, the silence grows as the climber begins to speak.

“Although awash in resemblance, twas not I who chipped that rock.  For the Principle of Indiscernibility of Identicals is subject to no man’s will.  He who you detest is no longer, and I cannot be held culpable for his actions.”

The angry mob disperses in despair for the culprit is gone and justice cannot be given.

Reality is a tricky thing to think about.