All men are mortal, No stones are mortal, ∴ No stones are men.
Here the middle term _mortal_ is distributed in the second premise as in it the subject “_stones_” is _excluded_ from the entire mortal territory. This conclusion is verified by the formal statement that “E” distributes both subject and predicate. Since all of the “men” circle belongs to the “mortal” circle and none of the “stones” circle belongs to the “mortal” circle then none of the “stones” circle can belong to the “men” circle.
(4) _No term must be distributed in the conclusion which is not also distributed in its premise._
It has been affirmed that a term is distributed when it is referred to as a definite whole. To put it in another way, a term is distributed when it is employed in its fullest sense. It is obvious that we should not employ a term in its fullest sense in the conclusion when it has been used only in a partial sense in its premise. What is said of the part cannot necessarily be said of the whole. For example: Because _some_ men are honest it does not follow that _all_ men are honest. Of course the converse of this is true, namely, if it could be proved that all men are honest then surely it would follow that some of the men are honest. To put it briefly: What is true of _all_ is true of _some_ but what is true of _some_ is not necessarily true of _all_.
To distribute a term in the conclusion when it is not distributed in the premise where it occurs is equivalent to saying, “what is true of some is true of all.” This error which violates rule “4” leads to the two fallacies of illicit process of the major and minor terms. The following illustrate the two fallacies.
All trees grow, No men are trees, ∴ No men grow.
The first premise is an A and consequently its subject is distributed. The second premise and conclusion being E’s have both subject and predicate distributed. Thus _grow_, as used in the conclusion, is distributed, but, as used in the major premise, it is not distributed. Fallacy shown by circles:
Here all of the “tree” circle belongs to the “grow” circle and none of the “men” circle belongs to the “tree” circle, hence the diagram correctly represents the meaning of the two premises and shows the fallacy of concluding that _no men grow_. The “men” circle, being entirely within the “grow” circle, indicates that _all men grow_. Syllogism illustrating illicit minor: