Originally Posted by sordavie

No no, that's clearly a version of the slippery slope fallacy you're making then.

If people keep whaling then whales will go out of existence. Then they will hunt some other species. Then that will go out of existence. Then another. And soon enough there won't be enough biodiversity. And they're just doing this for profit. And anyone who does that is evil. The Japanese do that. Therefore, the Japanese are evil for caring only about profit over biodiversity.

You began with a relatively small step that you reason will inevitably lead to some chain of events culminating in some significant consequence. This type of fallacious reasoning is highly prevalent in bad political reasoning. For instance: If we pass laws against fully-automatic weapons, then it won't be long before we pass laws on all weapons, and then we will begin to restrict other rights, and finally we will end up living in a communist state. Thus, we should not ban fully-automatic weapons. This might sound like an appealing argument to some people - perhaps because they are against such a ban - but it's a poor argument. It does not present a good reason against banning fully-automatic weapons.

It's a misapplication of the rule of transitivity. Transitivity states that if A entails B and B entails C, then A entails C. So someone making the slippery slope fallacy reasons: A leads to B. B leads to C. C leads to D. Therefore, A must lead to D. But this notion of "leads to" is quite different than the notion of entailment. If A entails B, then A could not possibly happen without B also happening. In other words, A's happening necessarily gaurentees B's happening. But this is not so with "leads to" or related ideas like "causes." These concepts are not transitive. Consider the following argument:

If you bring life in to the world then you cause someone to exist. Conceiving of a child causes existing causes the child to come in to existence. Their being in existence causes them to be alive. Their being alive causes them to be mortal. Their mortality causes them to eventually die. Therefore conceiving of children is causing individuals to die. To cause the death of an individual in this way (not through self defense or proper warfare or the like) is murder. Therefore all mothers and fathers are murderers.

That's clearly a bad argument. The reason? 'Causes' is not a transitive term. One cannot infer from A causes B, B causes C, and C causes D to A causes D. But that's exactly what you're doing with your argument that the Japanese whalers are evil.

Hmm I see you are taking this to another level. I'd have to dig up my old 'logic' book to follow you there and I could probably not.

Some remarks though.
I wonder if this is really applicable, in that we are dealing with such complex problems, that I suspect it may not be possible to simplify them to the logical exactness you propose. It might simply mean the end of the discussion.

*I don't propose a chain of event like you wrote down I think. What I proposed I think is something like:

biodiversity is related to human extinction
Whales are an element of biodiversity
whales are related to human extinction

Then I would infer that making whales extinct trough hunting, could (normally I would say would but that is not certain) related to human extinction.

Then about the 'evil'. in a philosophical sense, to me there is no good and evil. So I'm not bothered about the word. It is something used in daily conversation. Instead I could say: counterproductive for the goal of human subsistence.

So what's the verdict? .