When does something cease to exist?

Question

For humans, legally speaking, someone who's "brain dead" is confirmed to have ceased to exist. But what about philosophically speaking? What makes someone who they are? If we are our bodies, the body exists after "brain death". Why doesn't that mean that we would still exist despite "brain death" and cessation of all bodily function? Even if the body turns to ashes, why wouldn't that mean that the body continues to exist in the form of ashes? When does the body truly cease to exist and move from existence to non-existence?

This question encompasses everything: inanimate and animate objects alike. For example: a chair is turned to ashes. Why wouldn't that mean that the chair continues to exist in the form of ashes? When does the "chair" truly cease to exist and move from existence to non-existence?

Answer 1

IMO this is nothing more than a question about how we define words. If we have a definition of ‘chair’ and something stops meeting that definition then it’s no longer a chair. If we named a group of atoms that at one point comprise a chair and we have some way to keep track of them all then burning the chair (for example) won’t make that group cease to exist. When applied to a human, there’s a certain amount of latitude since most of the time we don’t need to worry about physical form vs. identity. If you’re a doctor then you might interpret ‘human’ as stopping at death, while if you’re an undertaker you might not. There’s nothing that obliges us to define words in any particular way except consensus between people who use those words.

Answer 2

In the example of the chair, the chair ceases to exist when its component parts no longer serve the human purpose for which the chair was made.

Aristotle found four causes are necessary before change can occur:

Material cause, or the stuff out of which something is made (here, pieces of wood);

Efficient cause, or the process of transforming the material cause into something else (the manufacturing process);

Formal cause, or the ultimate form after the transformation has ended (four legs, a seat, and so forth); and

Final cause, or the purpose which the first three causes are intended to fulfill (to sit).

Here, the process is inverted; it travels away from a form useable to people instead of towards it. The formal cause (the completed chair) becomes the material cause. The efficient cause (fire) is that which destroys, not creates. The material cause becomes the formal cause (here, a pile of ashes).

The chair has ceased to exist when it cannot be used for its intended purpose, when it fails to accomplish the final cause. Here, that will probably happen sometime during incineration.

Answer 3

Suppose to light the chair on fire, and it burns, and it turns into ashes. I think the easiest way to understand that philosophically is to not try to draw an infinitely precise line between existing and not-existing. At the beginning the chair exists unburnt, and then once it is set on fire, it is in a state where it both exists and doesn't exist, and once the fire is out and it's just ashes, it wholly doesn't exist.

If you want to try to find a moment when the chair has just ceased to exist (the previous moment it existed, let's say), then I think a good line to draw would be when it is recognizable as a chair. At some point, say, it will collapse and just be a pile of burning wood. This collapse event might be fast enough to satisfy your urge to put things into binary categories.

Answer 4

You can make it as complicated as you wish, but it simply depends on your definition of "exist" and of the object you are considering. Define that and you have your answer. Mind you event, even that can be contentious. Take @markandrews answer from Aristoteles. A chair is (a.o.) something with four legs. You break one of its legs. Is it still a chair? It surely is a broken chair. So giving a good definition of an object is not in most cases not easy. Which is, of course, great news for philosophers !

Answer 5

Simply speaking the move (from existence) to a non-existence state is happening when the object stops interacting with the environment. So in order to answer this question you have do define "interaction" and "environment". So for example if in my dreams (environment) my dead grand-mother "speaks" with me (interaction ) then she is in existence. Hope that helps.