The argument from culture/heritage has been widely used to justify a wide range of societal practices, eating animals is no exception. This argument asserts that because something is ingrained in a culture or it is what a person was raised to believe, it is morally acceptable as a result. In order to assess the validity of using culture as an ethical defence for eating animals, it is first necessary to establish what we mean by “culture.”
Loosely defined, culture refers to the ideas, customs, and social behaviour of a particular people or society. When people use this defence, this is largely the definition they are working with. Even from point of definition, an obvious weakness with this argument should become clear. When we say “this is in our culture,” all we really mean is “this is how we behave as a group.” When framed this way and distinguished from the things groups do out of necessity, it is obvious how utterly ludicrous this defence really is. Essentially what we are saying here is “this is ethically justified because this is the way our society behaves.” The person making this claim is arguing that eating animals is okay because it is in our culture, and it is in our culture because we eat animals. This is a clear example of circular reasoning and is therefore logically invalid.
Not only is this logically invalid, if we accepted the conclusions of this logic we would be in a position where we could justify almost anything on the grounds that it is an inherent part of our culture. Racism is also deeply ingrained in many cultures, as is sexism and classism; that does not make these attitudes, behaviours and values any less unethical. Some groups have a culture of aggression, of intolerance and intimidation, that these things are cultural is not in any way ethically relevant. To concede that actions are morally permissible if they are a part of a culture or heritage would leave us with very few acts we could consider truly immoral. A defender of this argument may want to intercede with the classic “ethics are relative to cultures” argument, but this would not be helpful in this case since, as we have already stated, plenty of behaviours are widespread across several cultures which are not generally considered to be ethical.
When this argument is framed in terms of our heritage, the central premise simply changes from “this okay because our culture does it now” to “this is okay because our culture has done it in the past.” Once again, this falls victim to the same criticisms as the previous incarnation of this argument, and in addition, it suffers the additional flaw of assuming that since things were done a certain way, they must continue to be done that same way now. This conclusion does not follow from the premise. The previous practices of a society in no way predetermines the future behaviour of said society, so long as said behaviour is not a necessity for survival. That we have been raised a certain way, with certain emotional attachments to specific behaviours, makes our repetition of these behaviours understandable, but not permissible.
This argument and other versions of it are, despite their insistence otherwise, dispensing with ethics and simply stating “it is okay to do this because that is the way things are.” This is not only a poor defence, it is not an ethical defence at all. To accept this argument would be to accept that whatever behaviour we currently practice as a culture and would rather not change is ethical. This moral apathy may be common, but that does not make it right, and the consequences for accepting such reasoning would be extremely dangerous.