But we must not forget, what logicians seem occasionally to overlook: that the 'undistributed middle,' while it interferes with absolute proof, may be quite consistent with a degree of probability that approaches very near to certainty.

Both the Bertillon system and the English fingerprint system involve a process of reasoning in which the middle term is undistributed.

But the great probabilities are accepted in practice as equivalent to certainties." Mr.Winwood grunted a grudging assent, and Thorndyke resumed: "We have now furnished fairly conclusive evidence on three heads: we have proved that the sick man, Graves, was Jeffrey Blackmore; that the tenant of New Inn was John Blackmore; and that the man Weiss was also John Blackmore.

We now have to prove that John and Jeffrey were together in the chambers at New Inn on the night of Jeffrey's death.
"We know that two persons, and two persons only, came from Kennington Lane to New Inn.

But one of those persons was the tenant of New Inn--that is, John Blackmore.