2018/75: Freedom and Necessity -- Steven Brust and Emma Bull

2018/75: Freedom and Necessity -- Steven Brust and Emma Bull

Beside your letter, as empirical and sensible as any Rationalist might pen, mine seems full of "a host of furious fancies." Well, I am resolved to let our mystery spin itself out as a philosopher's experiment. [loc. 146]

Reread on the occasion of its becoming available in ebook format. Apparently I first read this in 1997: original review here.
( slightly spoilery )