argument against materialism from moral accountability (revised)

Imagine that ‘Sally’ (S) robs a bank (call this event R) in 1975 (t1) and is caught. However, due to various complications with the prosecution, she is not put on trial until 2011 (t2). During this time, via natural processes, various atoms that compose her body have been replaced with other ones. Now for the argument.

Let’s say that x “strictly survives” some occurrence if x exists before that occurrence and x exists after that occurrence.

1. A person can be morally accountable for an event iff they are numerically identical to an object that causally contributed to that event.
2. S at t1 is the only object that causally contributed to R which S at t2 could be numerically identical to.
3. From (1) and (2), S can be morally accountable for R’s occurrence at t1, even at t2, iff S at t2 is numerically identical to S at t1.
4. If S is a material object, S lost some composing parts between t1 and t2.
5. From (3) and (4), if S is a material object, S can be morally accountable for R’s occurrence at t1, even at t2, iff S strictly survives the loss of some of her parts.
6. S can be morally accountable for R’s occurrence at t1, even at t2.
7. From (5) and (6), either S is an immaterial object, or S is a material object that strictly survives the loss of some of her parts.

8. Material objects cannot strictly survive the loss of any of their parts.
9. From (7) and (8), S is an immaterial object.

Premise 8 is the most contentious one, and below is an argument to support it. The argument does not originate with me, a friend posted it on a theologyweb thread (and apparently it is well-known in the literature anyway).

“Consider your body. Name it “Body”. Consider the part of Body that consists of all of Body except your left pinky. Call that part “Body-minus”. At time t0, let’s say, Body is intact; it includes your left pinky as a part. Suppose that at t1, however, your left pinky is annihilated. Call the pinkyless, human-body-shaped, material object that remains in your vicinity after this unfortunate event “Deformed”. Note that the following argument appears to be sound:

(1) At t1, Body-minus still exists (because nothing happened to Body-minus except that something external to it was detached from it).
(2) At t1, if Body still exists, Body is identical to Deformed [What else could Body be at that time?].
(3) At t1, if Body-minus still exists, Body-minus is identical to Deformed [What else could Body-minus be then?].
(4) At t1, Body-minus is identical to Deformed [This follows from 1 and 3].
(5) At t1, if Body still exists, Body is identical to Body-minus [This follows from 2, 4 and the fact that identity is an equivalence relation].
(6) At t1, it is not the case that Body is identical to Body-minus [Note, for example, that at t1 if Body and Body-minus both exist, they have different historical properties – Body-minus used to be a proper part of Body, for example, but Body was never a proper part of Body].
(7) Therefore, at t1 it is not the case that Body still exists [5,6].”

A parallel argument could be given with respect to any material body that is said to have survived the loss of a part, so it seems that premise 8 in the first argument is true.

argument against materialism from moral accountability

[Rough sketch]

Imagine that Sally (S) robs a bank (call this event R) in 1975 (t1) and is caught. However, due to various complications with the prosecution, she is not put on trial until 2011 (t2). During this time, via natural processes the atoms that compose her body have been completely replaced with other ones. Now for the argument.

1. S is morally accountable for R’s occurrence at t1, even at t2.
2. Substances are the only things that can cause events.
3. Only the thing that caused an event can be morally accountable for that event.
4. If materialism is true then S at t1 is not an identical substance to S at t2.
5. From (2), (3) and (4), if materialism is true then Sally is not morally accountable for R at t2.
6. From (1) and (5), materialism is false.

moral accountability argument (extended and reworked)

1. X is any instance of an agent (A) being animated that is morally relevant.*
2. X is either caused or uncaused.
3. If X is uncaused then A didn’t cause X.
4. If A didn’t cause X then A is not responsible for X.
5. If A is not responsible for X then A is not morally accountable for X.
6. From (3), (4) and (5), if X is uncaused then A is not morally accountable for X.

7. If X is caused then X is preceded by a causal chain.**
8. All causal chains are either infinite, finite, or circular.
9. From (7) and (8), if X is caused then X is preceded by either an infinite, finite, or circular causal chain.

10. If X was preceded by an infinite causal chain then the causal chain either occurred entirely within A’s agency, or extends outside of it.
11. It is impossible for there to be an infinite causal chain within A’s agency.
12. From (10) and (11), if X was preceded by an infinite causal chain then it extends outside A’s agency.
13. If X was ultimately caused by things outside of A’s agency then A is not ultimately responsible for X.
14. If A is not ultimately responsible for X then A is not morally accountable for X.
15. From (12), (13) and (14), if X was preceded by an infinite causal chain, then A is not morally accountable for X.

16. If X was preceded by a circular causal chain then X is ultimately the cause of itself.
17. It is impossible for X to be the cause of itself.
18. From (16) and (17), it is impossible for X to be preceded by a circular causal chain.

19. If X is preceded by a finite causal chain then the causal chain had a beginning.
20. All causal chains that have a beginning have a first cause.
21. From (19) and (20), if X’s preceding causal chain is finite it has a first cause.
22. If X’s preceding causal chain has a first cause, that cause is either A or not A.
23. If the first cause in X’s preceding causal chain is not A then A is not ultimately responsible for X.
24. From (14) and (23), if A is not the first cause of X then A is not morally accountable for X.
25. From (2), (6), (9), (15), (18), (21) and (24), if A is not the first cause in a causal chain preceding X, then A cannot be morally accountable for X.

26. Necessarily, the first cause in a causal chain cannot itself have a cause.
27. All contingent causes are themselves caused.
28. From (26) and (27), if A contingently causes X then A is not the first cause in the causal chain preceding X.
29. From (25) and (28), if A is not necessarily the first cause in a causal chain preceding X then A cannot be morally accountable for X.

*The language of being “animated” in “morally relevant” ways is used to refer to an agent’s action without using language that already presupposes that the agent is the responsible party. Look at the difference in language, say, between “an agent moving his hand” and “an agent’s hand moving”. The first implies that the agent is responsible, the latter leaves that open. In the same way being animated in morally relevant ways refers to an occurrence that is morally significant (say murder, or rape), without suggesting an a priori commitment to what the responsible party is, i.e. it could be an alien tapping into the agent’s brain, or indeed the agent herself.

**To some people “causal chain” might suggest that there is definitely more than one preceding cause. I don’t take that phrase to have any quantitative input in this argument (there could just be one preceding cause – it would still quality as a causal chain here).

we are morally accountable for our choices so long as we necessarily make them.

1. X is any way an agent (A) can be animated that is morally relevant.
2. A is morally accountable for X iff A is responsible for X.
3. A is responsible for X iff A is the ultimate cause of X.
4. From (3) and (4), A is morally accountable for X iff A is the ultimate cause of X.
5. A cannot be an ultimate cause of X unless A causes X.
6. From (4) and (5), if A does not cause X then A is not morally accountable for X.

7. If A causes X then A does so either necessarily or contingently.
8. Of metaphysical necessity, any contingent occurrence has itself got a causal explanation.
9. If an occurrence has itself got a causal explanation then that occurrence cannot be the first cause in a causal sequence.
10. If an occurrence is not the first cause in a causal sequence then it is not the ultimate cause of the causal sequence.
11. From (4), (8), (9) and (10), if A causes X contingently then A is not morally accountable for X.

12. From (6), (7) and (11), A can be morally accountable for X iff A causes X necessarily.

(Note: The language of being “animated” in “morally relevant” ways is used to refer to an agent’s action without using language that already presupposes that the agent is the responsible party. Look at the difference in language, say, between “an agent moving his hand” and “an agent’s hand moving”. The first implies that the agent is responsible, the latter leaves that open. In the same way being animated in morally relevant ways refers to an action that is morally significant (say murder, or rape), without suggesting an a priori commitment to the responsible party.)