|A Scientist Who Regularly Engages in Philosophy Without Realizing It|
Consider two similar examples. Imagine a Christian, instead of engaging with the arguments of a Buddhist or Astrologist saying, "That's not religion. Religion is Christianity." Or suppose a Democrat were to say to a Republican advancing an argument against national minimum wage laws: "Get off it. What you're saying is not politics."
This is not to say that there aren't clear cases where something is or is not science. Riding a bike ain't science nor is painting. Though there is a demarcation problem regarding what counts as science, some particular areas of science such as biology, chemistry, and physics are well defined areas of inquiry.