I recently discovered a standard way of formulating logical discussion as an argument map on the blog philosophical disquisitions. Basically this involves taking a starting point, making arguments that follow from the starting point, then drawing a conclusion. The clever part is that you show counterarguments (e.g. does this really follow? Can we conclude that from the preceding points?) back and forth until one side of the debate wins.
I’ve drawn up my essay on vegetarianism in argument map form. The stages building up the argument are below; you might prefer to look at the high resolution pdf of the full thing, and a pdf slideshow introducing the arguments in the stages below, or a cleaner pdf without a background.
Perhaps “Animals are included in the system” needs justification; but in this system, we can argue why it shouldn’t be true instead. The same set of arguments come out in the end.
Here we attack the argument in two places; should we include animals in the system morality, and can we eat them anyway if we do? Of course, it is possible to attack the assumption of morality being something to aspire to. The alternative assumptions appear later, and I discuss the issue at length in my essay. Most of us do aspire to being moral at some level.
Now I’ve introduced evidence and argument as separate things. However, in the map they appear quite similarly. In the “Animals have no souls” I’ve allowed the implicit assumption that there is a real thing called the soul, because anyone citing the religious argument might make this assumption (even though I personally do not). This is because I don’t think the soul argument permits animals to be mistreated (i.e. excluded from morality) even if it were true. The evidence for culture and language in animals of course don’t mean they are as complex as in humans; simply that they do exist. So we can still claim to be superior to animals but only by a matter of scale, which doesn’t exclude animals from the system of morality (though places less emphasis on their needs relative to ours).
Here, the two consistent assumptions that I can see against vegetarianism appear: either we make a religious assumption and take the holy texts as our literal source of moral commandments, or we accept that we don’t think morality is a real thing to aspire to.
Finally, the full argument map is completed. The “Benefit of the doubt” argument is clearly the most important one here; there are only two ways around it as far as I see. Firstly, we can do more science and remove the doubt; this is still a very long way away from what science can achieve though as it requires a full understanding of animal and human consciousness. Secondly, the “duty to give the benefit of the doubt” argument could be attacked, although I don’t personally see how.
I see the argument for vegetarianism as being very well supported here, because we only need doubt to be able to defeat any other counter-argument. Now its been expressed clearly, can anyone add any red boxes to attack the remaining yellow?