Is Turley right?

Reader Albert J. Brooks wonders whether Jonathan Turley is correct in asserting that Roberts' stated need to recuse himself in a certain class of cases makes him an inappropriate nominee:

The Constitution and federal law provide for a Supreme Court composed of nine justices. Obviously there will always be unforeseen situations (illness, etc) when one or more Justices can't sit in decision on a case. And there are other cases that could not have been foreseen when the Justice was appointed in which he or she cannot sit due to a conflict of interest.

But when a Justice, for whatever reason and with respect to whatever issue, states ahead of time that he will recuse himself on that issue, is it appropriate or even permissible for the President to nominate and the Senate to confirm the Justice; essentially committing to a Supreme Court of 8 Justices on that particular issue?

Are we entitled to Justices who'll interpet and apply the Constitution and the laws of the United States? And is a Justice who'll commit to doing so, either in light of or without regard to his or her morality, preferable to a Justice who will simply "sit out" some tough cases?

Rob