I'm currently doing a PhD in computational biology, but I have other interests like music and ceramics, and I'm lucky enough to be at a university with excellent programs in both. I've wanted to take a course in either of these fields for the 3 semesters so far I've been here, but my advisor won't approve and sign off on them. I have a free slot this spring and I really want to take a course just for fun, and to learn from the world-renowned instructors. I've tried negotiating about just taking an evening class, or having my work for him improve since I'll be happier overall, but he's just stuck on "this isn't your field". Who's being unreasonable here?
Do I have "the right" as a grad student to take a class just for fun?
I think phrasing the question as you did is slightly the wrong way of looking at the situation. It is more correct to say that you have the right to be treated with respect by your advisor. This includes having the advisor recognize that you are an intelligent human being with many dreams, hopes, ambitions, and a rich set of interests that go far beyond “doing research in computational biology”, and that the years you are now spending at a university community with leading experts in so many fascinating areas of human knowledge are an amazing and unique opportunity for you to pursue those interests and grow and develop as a person.
To be honest, I feel sorry for your advisor for being so short-sighted and narrow-minded that he cannot understand why taking these classes is important to you. It does not sound like he is treating you with the respect you deserve, and by failing to respect you I think he is also failing to respect himself and to be the decent person that I assume he wants to be and might believe himself to be.
Finally, your question reminds me of a part of Steve Jobs’ 2005 commencement address at Stanford. Talking about his days as a college dropout taking random classes to pursue his eclectic interests, he says:
Reed College at that time offered perhaps the best calligraphy instruction in the country. Throughout the campus every poster, every label on every drawer, was beautifully hand calligraphed. Because I had dropped out and didn’t have to take the normal classes, I decided to take a calligraphy class to learn how to do this.[...]
None of this had even a hope of any practical application in my life. But 10 years later, when we were designing the first Macintosh computer, it all came back to me. And we designed it all into the Mac. It was the first computer with beautiful typography. If I had never dropped in on that single course in college, the Mac would have never had multiple typefaces or proportionally spaced fonts. And since Windows just copied the Mac, it’s likely that no personal computer would have them. If I had never dropped out, I would have never dropped in on this calligraphy class, and personal computers might not have the wonderful typography that they do. Of course it was impossible to connect the dots looking forward when I was in college. But it was very, very clear looking backward 10 years later.
I know this doesn’t help with the practical question of what you should do, which others have commented about, but I thought I’d offer my take on the philosophical aspect of your question. Keep dreaming, and good luck!
I once took courses that were not directly in my field. I think it is appropriate but I would just listen to your advisor -- it's easier in the long run. Perhaps take some courses / participate in events at a place like a church, the Y, student groups or clubs, etc.
NOTE: At some places, they expect grad school to be your ENTIRE life, so this is not unexpected, though perhaps not fair. My advisor wasn't like that.
There isn't an absolute answer to the question: the rights and responsibilities of a student vary between universities, and are probably set out in writing somewhere. At my university, any student could attend lectures in almost any subject (practical labs and medicine are the exceptions that I can recall), although etiquette was to ask permission from the lecturer in advance.
Without seeing the regulations for your university, we can make some inferences.
Do I have “the right” as a grad student to take a class just for fun?
I think you answer that question yourself:
my advisor won't approve and sign off on them.
If you need approval from your supervisor, then you don't have the (unrestricted) right.
However, the body asks a different question to the title:
Who's being unreasonable here?
To answer that, you have to get at why you need your advisor to approve and sign off.
Are the courses you take assessed to determine your progress? If so, your advisor is being reasonable: unless you can show how studying music or ceramics will improve your understanding of biology, the course would skew the assessment.
Do the courses need to be paid for? If so, who's paying?
If it comes down to thinking that you should be thinking about biology 24/7 then the advisor is being unreasonable, but the need to obtain approval hints at a good reason.
Ask the graduate program director in your department, or some other department administrator. Ask in general terms, with neutral language. That is, avoid terms such as "unreasonable" and avoid finger pointing.
If the answer is "It's perfectly all right, and it's none of the advisor's business, as long as the student strikes a good work-life balance," then go ahead and describe your difficulty. I expect you could get a department signature. (Avoid unnecessary conflict, and don't tell your advisor you made an end run around him.)
If I were the department administrator, I would sign your form with alacrity, and say
I'm glad you've found a rewarding hobby.
Well, maybe you are both being unreasonable. Do you have the "right"? Of course you do. Do you have the right to do it while committing to your current degree program. Perhaps, or not. That would depend on the rules in place at your institution as well as the wishes of your advisor.
I'm just going to guess that the advisor is concerned that you will not spend sufficient effort on the tasks associated with the degree if you take something extraneous. That may be a legitimate concert. It would be especially important if you are doing joint lab work with others.
It is normally a bad idea to go against your advisor's wishes. He has some say in your future and you want him to be happy to support you now and in the future. After you finish you can do as you please, of course.
You could also, take a course from a different institution. That would add to your load, of course and the advisor might still object if he learns of it, based on your level of commitment.
Perhaps the advisor is telling you something important about his view of your progress and what you need to do to succeed in comp-bio. Think about it.