I’m actually a bit more relaxed about it — but not much. If you’ve closely paraphrased a philosopher’s definition of an ethical theory, then I’ll let it go.
If you use quotation marks around the part that you’re using from someone else, but forget to put the citation in, then I’ll let it go.
If I notice that your paper is unusually well-written for a freshman philosophy course — I’ll Google a unique sentence — if I find it and others, you’re busted — big time.
Good general advice — if someone else is saying exactly what you’d like to say, use a quote and give credit — then explain why that quote is a key part of your argument…. otherwise, put it in your own words.
Philosophy papers aren’t research papers — a research paper tells me what other people know about the subject. A philosophy paper is more difficult, because you have to think about the subject yourself. As a former student, now psych grad student, said of my dissertation — “it’s hard to make stuff up, how do you do it?’ — I just smiled and told her that’s how we do research — we read other people’s stuff and then make stuff up about the topic… She said she’d rather run experiments on undergrads… fair enough.