The education secretary has indicated to MSPs that Scottish students may face charges after they graduate.
Answering questions from members of Holyrood's education committee, Mike Russell said he disagreed with payments but he was not ruling them out.
He described the financial outlook for universities as "grim".
Mr Russell confirmed a range of potential measures to keep universities afloat will be in a Scottish government discussion paper published next month.
Tuition fees were scrapped in Scotland 10 years ago but replaced by a charge of about £2,000, to be paid after graduation.
This charge was abolished in 2008.
Mr Russell was speaking as thousands of students were demonstrating in central London against plans to almost treble tuition fees and cut university funding in England.
Under UK government plans, some university courses could charge up to £9,000 per year.
Universities Scotland, which represents higher education principals, has led calls for a contribution from graduates in Scotland towards the cost of their degree.
But Mr Russell told MSPs: "I am not agreeing with that at this stage.
"I'm not ruling it out, and I think it would be a pointless debate if I were to tell you before the debate was really under way what I was going to do and what I wasn't going to do.
"I am not ruling it out but I am perfectly happy to say that I disagree with it.
"I disagree with it because the Scottish tradition of higher education is one in which the state takes primary responsibility."
Mr Russell said the funding changes in England "clearly and explicitly" land students with the main responsibility for funding their courses, instead of the state.
"That is what is being openly said and what is being demonstrated against today in London," Mr Russell added.
"I believe the state has the primary responsibility in Scotland, therefore I do not accept automatically that there should be a graduate contribution."
He also voiced reservations about asking individuals who have been through "particular parts" of education to pay for that.
He added: "Where do we stop? If higher education is an advantage, is learning to read and write an advantage?
"Should individuals who are then taught to read and write pay more in taxation? I think you need to be very careful about this."
Mr Russell told MSPs that funding options for the future of universities and colleges will be set out in a green paper in December and the debate it prompts could be a "matter of contention" at next year's Holyrood election campaign.
The education secretary hopes that the incoming administration next May - of whatever political colour - will legislate quickly on reforms so they are in place by 2012, in line with the timescale for change south of the border.