### Aristotle - The Organon ANALYTICA POSTERIORA Book 1 Part 29

## One can have several demonstrations of the same connexion

1.
One can have several demonstrations of the same connexion not only
by taking from the same series of predication middles which are
other than the immediately cohering term e.g. by taking C, D, and F
severally to prove A-B - but also by taking a middle from another
series.
Thus let A be change, D alteration of a property, B feeling
pleasure, and G relaxation. We can then without falsehood predicate
D of B and A of D, for he who is pleased suffers alteration of a
property, and that which alters a property changes. Again, we can
predicate A of G without falsehood, and G of B; for to feel pleasure
is to relax, and to relax is to change. So the conclusion
can be drawn
through middles which are different, i.e. not in the same series - yet
not so that neither of these middles is predicable of the other, for
they must both be attributable to some one subject.

2.
A further point worth investigating is how many ways of proving
the same conclusion can be obtained by varying the figure.

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