Hi Everyone!
Yes, it is me, asking a question. I am in the process of finishing up my latest book and I have one argument in there that I am not sure about. I want to make sure that I am not missing anything obvious (it happens). So here we go. This is a criticism of an argument by Peter Singer. His argument is presented as follows:
- In order to conclude that all and only human beings deserve a full and equal moral status (and therefore that no animals deserve a full and equal moral status), there must be some property P that all and only human beings have that can ground such a claim.
Any P that only human beings have is a property that (some) human beings lack (e.g., the marginal cases).
Any P that all human beings have is a property that (most) animals have as well.
Therefore, there is no way to defend the claim that all and only human beings deserve a full and equal moral status.
What follows is my write up of a problem I see with this argument. Your feedback is appreciated...
The Sufficient But Not Necessary Problem
Recall that conditions could be necessary or sufficient. Singer’s version of the argument ignores the possibility of
sufficient conditions. This is a major problem for the soundness of the argument. Consider the following modification to the argument:
- In order to conclude that all and only great students deserve a full scholarship (and therefore average students do not), there must be some property P that all and only great students have that can ground such a claim.
Any P that only great students have is a property that (some) great students lack (e.g., the marginal cases).
Any P that all great students have is a property that (most) average students have as well.
Therefore, there is no way to defend the claim that all and only great students deserve a full scholarship.
We have a problem with the first premise. It is false that there must be some property that
all and only great students have (i.e., a necessary condition). There can also be some property that only but not necessary all great students have. If we ground a “great student” with having one of the following properties: a 4.0 GPA, a 1600 on their SATs, or won a Nobel prize then any of those properties would be
sufficient to be part of the “great student” group deserving of a full scholarship. It can also be the case that students with at least two of the three properties would be deserving of the full scholarship. In such a case, it is not true that there must be some property that neither
all nor
only great students must have. Because of this, the rest of the argument falls apart.
Just as it not true that “in order to conclude that all and only great students deserve a full scholarship, there must be some property P that all and only great students have that can ground such a claim,” it is also not true that “in order to conclude that all and only human beings deserve a full and equal moral status, there must be some property P that all and only human beings have that can ground such a claim.” It is tempting to simply accept Singer’s argument as sound because we might agree with the conclusion, but this would be fallacious reasoning. It would be as problematic as concluding that the earth is not flat because nobody you’ve ever known fell off the edge.