My response was to parody the statement I was responding to, specifically "Veganism has no solid basis in that there is no precedent." I was hoping replacing just one word would have made the connection as clear as possible. Is having no precedent enough of an argument to stop change? It's absurd on its face.
A) There is plenty of precedent for women being involved in the mechanisms of government
B) Governance is a cultural artefact and diet is a matter of biology. I do not think we perfectly understand culture, but we create it as we go along. The requirements of biology are hard, must be met, and very poorly understood. SO lack of precedent for veganism (plenty for vegetarianism) is an issue
Why fight over a minor problem with my example? If you can't come up with a parallel statement that shows the absurdity of the claim, you're not trying hard enough.
Pick a society that didn't have women voting; imagine someone making the argument "there is no precedent", and notice how it's an absurd argument. It sounds like a conservative's wet dream, implying that whenever there is no precedent for something, it meaningfully counts against that thing. Sure, there is no precedent for surviving a guillotine, but are you saying the intention of my sentence wasn't clear?
How about this, at some point in history someone could have said "there is no precedent for the internet" -- would that have been a meaningful "con" against creating it?
As my follow up question goes: "How many examples of vegan people living healthy lives into their 90s would be enough to convince you?"
A good parallel about veganism is from the past: people were saying "hey, we shouldn't have slaves" and slave owners saying "but I like it this way". To ignore the arguments of the anti-slavery movement by gesturing at some generic concern for well being is absurd. If in fact having no slaves meant that the rich families were going to have less money and would eat less-nutritious food is not a good argument for perpetuating slavery.