10/14/2018

EDIT: ADDED Oct. 16 2018: As Karim Zahidi notes in the first comment below, I made an elementary logical error in thinking that (1) is evidence for (2). So I have crossed out the original mistake like this below. But I still think the argument after that step may work: so now the argument just starts from (2) as a supposedly plausible claim, instead of trying to justify (2) via (1).

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This might sound initially like a too-clever undergrad ‘gotcha’ paradox. However, I think that at least for some folks who have perfectionist tendencies, the following is experienced as a genuine difficulty in their lives.

The following strikes me as plausible:

(1) It’s OK to make some mistakes.

If (1) is true, then it seems the following should be true as well, since it’s just a restricted version of (1):

(2) It’s morally OK to make some moral mistakes.

But

(3) Making a moral mistake is doing something morally impermissible,

and

(4) if something is morally OK, then it is morally permissible.

And (2)-(4) logically entail

(C) It’s morally permissible to do some morally impermissible things.

And (C) looks like a contradiction.

(For all I know this is already out there somewhere, but it was not on the interesting list of paradoxes of deontic logic in the Stanford Encyclopedia.)

At 16/10/18,  Karim Zahidi said...

I don't understand how the truth of (1) implies the truth of (2).

Consider the following analogical

(1)It is OK to eat some meat

(2) It is morally ok to eat some human meat

One could very well accept the truth of (1) while not accepting the truth of (2). This case seems to me to be structurally the same as the one you present. Or am i missing something?

At 16/10/18,  Greg Frost-Arnold said...

Hi Karim --
Thanks! I think you are 100% correct. This was a logical mistake on my part. I completely rescind the claim that (1) is evidence for (2). (And I'm going to edit the post accordingly now.)