Buddhism, Reincarnation, and Doubt Is it possible to maintain certain skeptical doubts about literal reincarnation and continue to work towards stream-entry, assuming one's practice is sincere and vigilant?
Is it possible to maintain certain skeptical doubts about literal reincarnation and continue to work towards stream-entry, assuming one's practice is sincere and vigilant?*

Yes it's possible.

Skeptical doubt about the (whole) Dharma, about Buddhism (in general), is a hindrance (I think it would hinder "continuing to work").

The fact that you do continue, sincerely, suggests  a certain absence of doubt.

I'm not sure what you mean by "maintaining" a doubt. "Reincarnation" might be a topic where you'd find it more useful to be agnostic (i.e. "I don't know, I'm not sure, I don't understand, let's put that topic aside for now") rather than either believing or disbelieving. It's apparently a topic on which different people disagree (though you'll often find people try to emphasize that the dharma is "birth" or "rebirth" and not "reincarnation"); leaving that aside, perhaps there are other (perhaps, even, more important) topics that it's good to ascertain.

The topic (of rebirth) might become clearer as you understand other aspects of dharma.

There's even the Kalama Sutta, which suggests that "doubt", at least initially, about doctrines you find doubtful, is proper:


  It is proper for you, Kalamas, to doubt, to be uncertain; uncertainty has arisen in you about what is doubtful. Come, Kalamas. Do not go upon what has been acquired by repeated hearing; nor upon tradition; etc.


To be honest I fear that "reincarnation" is a topic which puts many Westerners off Buddhism. All they know about it is, "Oh, Buddhism: that's something to do with reincarnation, isn't it? Well I don't believe in reincarnation, so I'm not interested in Buddhism." I think that's a mistake, though. Obviously a disbelief in reincarnation does prevent (some) people learning more/anything about Buddhism, but I think that isn't necessary so.

To "cross the stream" I suggest it makes sense to concentrate not (or not only) on what you doubt (e.g. "reincarnation").