Let us not digress into useless speculation,' Scott went on.

But neither of them had the mind to waste time in useless speculations.

The answer to that would involve a great deal of useless speculation on our part, Doctor, since we have no facts at hand.

Yet again, she forced this useless speculation from her mind.

Why fill up paper with a lot of useless speculations?

The police do not always allow useless speculation to grow when an obvious link may be misleading.

Kirk fully understood how useless such speculation could be, but he made no attempt to turn the attention of his officers to more practical matters.

In this approach, all attempts at conjecture about formal and final causes was rejected as useless speculation.

There was no answer to that, beyond the useless speculation of a possibility among improbabilities.

Let us avoid useless and costly speculation about the climate.