>>11341102You simply establish common ground with the reader by declaring the definition that will be used in the paper and maybe explain why you think that one is the most suitable definition. This is something that has to be made in order to even have a discussion. For example, you cannot have a debate on whether of not climate change is an ethical issue if the person you are talking to believes that climate change is not anthropogenic in nature but you believe it is. There is a word for this which I forgot, and maybe some anon will know it. But these assumptions are pretty much mandatory.
Then you look at philosophy as a whole (and its definition) and form an opinion, which you try to defend and make as strong as possible.
For example, using wikipedia's definition: "Humanities are academic disciplines that study aspects of human society and culture." This is a solid definition that encompasses humanities well enough, in my opinion. I would probably go over the definition and explain its significance and implications. Then I would use it to explain why I believe that philosophy is fundamentally a humanities (or isnt, depending on whatever I feel like).