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student of logic. He can easily work it out from what is indicated in Figure 2.
The most important deviation, however, from the ordinary course of opposition is that in which apparently universal propositions in A and E are contradictories instead of contraries, and either remove the possibility of I and O, or permit them under an entirely different conception from any that I have mentioned. I refer to such propositions as "Religion is true," "Science is absolute knowledge," "Vital force is electricity," "War is not an evil," "The existence of government functions is necessary to preserve order," "Truth is essential to man's welfare," etc. The same is true of singular propositions such as "Plato was a philosopher," " Socrates was wise." In these instances the contradictory does not follow the rule for opposition, which demands the use of "some," but is the same proposition with the opposite quality, such as "Religion is not true," "Socrates was not wise," etc. Nor is it any reply to this criticism of the discrepancy between formal logic and general practice to say that common discourse uses the term "contradiction" rather loosely and does not distinguish between the law of contrariety and contradiction, but vaguely refers to any inconsistency in the way of holding two propositions at the same time. This very apology would be a justification of the position that I am here maintaining; namely, that formal logic in its rules for opposition has very little to do with the regulation of actual practice and so does not describe the actual law
