When a thing can not be reasoned out, it may just as well be guessed out.

The guess is always easier than the dictionary, and, if successful, it answers just as well.

Moreover, the teacher has no way of distinguishing the pupil's replies which are due to the guess from those due to honest work.

I venture to say, from personal experience, that no one who has been through the usual classical course in college and before it has not more than once staked his all upon the happy guess at the stubborn author's meaning.
This shallow device becomes a substitute for honest struggle.

And it is more than shallow; to guess is dishonest.