A few pages further on Whately gives a totally different account of
reasoning, without being aware of his inconsistency.
'Every syllogism has three, and only three terms: viz. the
middle term and the two terms (or extremes, as they are
commonly called) of the Conclusion or Question. Of these,
first, the subject of the conclusion is called the _minor_
term; second, its predicate, the _major_ term; and third, the
_middle_ term, (called by the older logicians "Argumentum") is
that with which each of them is separately compared, in order
to judge of their agreement or disagreement with each other.
If therefore there were two middle terms, the extremes or
terms of conclusion not being both compared to the same, could
not be conclusively compared to each other.'[21]
Here reasoning is made to consist in comparing two things by
reference to a third which both resemble. There is not a word about
classification, which is declared just before--in loud capitals--to be
the universal principle of reasoning!