Feb 14, 2011

A new blog devoted to philosophy of religion

Interested in the philosophy of religion? I've started a new blog, Faith in Philosophy, designed to present the state of the art in academic philosophy of religion. You can read my introduction to the blog for more information about what's coming. And, if you're interested in discussing any recent books or articles, send me an email at faithinphilosophy@gmail.com.

How slippery is the slope?

The slippery slope fallacy is rather slippery. We often make claims about a slippery slope, and also accuse others of making the fallacy of the slippery slope. Which is it, a legitimate argument, or a fallacy?

It depends. We should distinguish several kinds of slippery slope arguments, neither of which is necessarily fallacious.

Let's suppose we're discussing eating dessert before dinner. You are in favor, and I am opposed. There are three kinds of slippery slope arguments I might make.


Tendency arguments: X tends toward Y
(1) Eating dessert before dinner tends to lead to eating lots of sweets.
(2) One shouldn't eat lots of sweets.
(3) Therefore, one shouldn't eat dessert before dinner, since one shouldn't do what tends to lead to something else that one shouldn't do.
This is a pretty reasonable prudential argument. (1) may be disputed, but the most controversial bit is drawing the conclusion (3) from the premises (1) and (2).


Necessity arguments: X always results in Y
(1) Eating dessert before dinner always leads to eating lots of sweets.
(2) One shouldn't eat lots of sweets.
(3) Therefore, one shouldn't eat dessert before dinner, since one shouldn't do what always leads to something else that one shouldn't do.
This argument reverses the weaknesses of the first: (1) is implausible (though potentially true as an empirical matter), whereas the inference from the premises to the conclusion is more sound.


Parity arguments: X is on par with Y

(1) Eating dessert before dinner is on par with eating too many sweets. (That is, if it's acceptable to eat dessert before dinner, then it's also acceptable to eat lots sweets.) 
(2) It's not acceptable to eat lots of sweets.
(3) Therefore, it's not acceptable to eat dessert before dinner, since it's not acceptable to eat lots of sweet and that is on par with eating dessert before dinner.
As with the second argument, the action is all in the first premise. The claim that two action types are on par from the perspective of morality or prudence is a substantive claim, and will likely to be controversial.

These are three varieties of the slippery slope argument. Each variety has some sound instances, and some unsound instances: neither one is always fallacious.

Having diagnosed the structures of these arguments and their distinctive weaknesses, we can see that accusing an interlocutor of making a slippery slope argument is a rather delicate matter. The first thing to do is get clear about which form of the argument the opponent is making. It's very common to mistake Parity arguments for Tendency or Necessity arguments. In those cases, the person making the allegation of a slippery slope is himself committing the strawman fallacy, since those versions of the argument are often weaker. The second thing to do is to pinpoint the disputed premise. For example, one sometimes hears the following argument against abortion:

(1) Abortion is just like infanticide. (Or: If abortion is acceptable, then so is infanticide.)
(2) Infanticide is wrong.
(3) Therefore, abortion is wrong.

This is an example of a Parity argument. While some philosophers dispute (2), the allegation of a slippery slope here is about the first premise. Once we identify that premise as controversial, the real work starts. (1) is a substantive moral claim. To rebut it, one points to features that distinguish abortion from infanticide. Once we start down that road, we are able to have a much more productive discussion than if we had simply rejected the argument as committing a slippery slope fallacy. Whether it does so is a substantive question.

So, the slippery slope fallacy is a slippery beast, and is perhaps best not thought of as a fallacy at all.

Ethics 'round the web

This weekend featured some interesting discussions of ethics, in the New York Times and elsewhere.

First, there's a nice article about high school ethics bowls. For philosophers who advocate for pre-college philosophy curricula, it's good to hear that some high schools are getting students involved in debating ethical issues.

This piece provides a good overview of the bioethics debate concerning a recent study on the effectiveness of fetal surgery for spina bifida. In this case, as with many others, there's a tradeoff between developing an effective study for a novel surgical technique and providing the best possible care for the patients.

Tauriq Moosa engages Don Marquis's argument against human embryonic stem cell research. It's a good read for anyone interested in stem cell research ethics.

Finally, Public Discourse has published three interesting essays on the ethics of false assertions, inspired by some recent events involving Planned Parenthood. Christopher Tollefsen argues against false assertions in this case, Christopher Kaczor takes the opposite view, and Tollefsen responds.

Feel free to comment if you've recently read some other good ethics or philosophy pieces.