Getting creative minds to put structure around and limits on their creative efforts can be a challenge, and may be the source of this schedule resistance. What you need to determine quickly is this: What is the real root cause of this person's dissent? Are they afraid
that anything they provide might not be accurate, and ultimately used against them to hold them to an impossible date? Do they think that all scheduling is overhead work that doesn't help them get their job done? Do they just take a hard stand on philosophical grounds, essentially saying, "It'll be done when it's done!"
Approach situations like this with a straightforward, head-on approach: Simply get together one-to-one with the individual and ask questions to uncover the real issue. Any problem can be solved if you know the root cause, work to reach a mutual understanding, and then work step by step to a solution.
To address the fear of being wrong, you may need to coach them through development of their part of the schedule. See our related question: Team member says they can't commit to any dates, which covers how to help a team member methodically develop their task list and estimates so the result is believable even to them. It also covers the impact project risks may be having on their willingness to participate and how to counter that impact.
The rest of this answer addresses the philosophical holdout, the person who seemingly believes scheduling is a non-value-added activity that is not required. This "artiste" is a special case many project managers encounter. They typically believe structure and numbers can't be put to their creative work and that it's meaningless to try. If they're not adequately involved in the big picture of the project and its goals, all the scheduling sound and fury looks like something to pin them down without providing them any particular value.
It may be helpful to point out the higher good—the project's need for this plan information. The company needs to have a completion date to communicate to customers, to provide a rallying point for every group's work to come together, to plan for when new revenue can come in so that we can all keep our jobs! If you can get the team member to acknowledge the larger business need and benefit of planning, you've got at least a foundation for getting their cooperation with the scheduling.
Then discuss how that individual and their efforts fit into the larger project plan. What impact might occur if the project didn't know when their part would be ready for integration with others' work, for example? How would they feel if they didn't know when to expect the work from group X that their work depends on? Build the understanding that they're a critical part of a larger effort and the schedule has a business purpose. Call them on their attitude that a schedule is nothing more than a pesky set of dates someone is setting just to limit them and micro-manage them to—it's just not true.
Of course, all this sounds great but perhaps you've tried this approach before and gotten nowhere. There are people who object so strenuously to planning that you may have to bring in higher powers. Before you do that (actually, before you do any of the above), make sure you are asking for something reasonable. Make sure you are not asking for certain detail just because schedule have always been done like this. What information do you and the team really need to create a good integrated plan and understand dependencies? Make sure you aren't inadvertently asking for schedule detail you really don't need to have. Once you've passed these sanity checks, it may be time to involve the project sponsor, who can then talk to your artiste's functional manager to reinforce the importance of their participation in the scheduling. Just don't go over their head until all collaborative approaches have been exhausted.