(3) All D is E.
All A is D.
.'. All A is E.
Regressive Sorites.
(1) All D is E.
All C is D.
.'. All C is E.
(2) All C is E.
All B is C.
.'. All B is E.
(3) All B is E.
All A is B.
.'. All A is E.
§ 815. Here is a concrete example of the two kinds of sorites, resolved each into its component syllogisms—
Progressive Sorites.
All Bideford men are Devonshire men.
All Devonshire men are Englishmen.
All Englishmen are Teutons.
All Teutons are Aryans.
.'. All Bideford men are Aryans.
(1) All Devonshire men are Englishmen.
All Bideford men are Devonshire men.
.'. All Bideford men are Englishmen.
(2) All Englishmen are Teutons.
All Bideford men are Englishmen.
.'. All Bideford men are Teutons.
(3) All Teutons are Aryans.
All Bideford men are Teutons.
.'. All Bideford men are Aryans.