This is a discussion tree based on many discussions with animal welfare advocates related to my Peter Singer discussion tree.
Is it missing an important argument? Comment below about what should be added.
Click the diagram to expand or view the PDF for selectable text.
See also: Posts about animals.
Rather than defend the moral value or general intelligence of animals, many people instead question the moral value or general intelligence of humans (especially babies, senile people, people with low IQs, and other groups that people are bigoted against). I may add nodes to the chart to cover that.
A quick answer to cover most of this is: conversations require creative guesses and criticism to figure out what the other person is saying. Babies listen and think creatively about what people are saying well in advance of babbling. General intelligence means being able to learn anything that can be learned, which is relatively easily visible in discussion because the meanings of sentences have to be figured out by learning. This is explained by Critical Rationalism, e.g. BoI. See also http://fallibleideas.com/communication-is-hard