A fallacy is defined as "an unsound argument or mode of arguing which, while appearing to be decisive of a question, is in reality not so; or a fallacious statement or proposition in which the error is not readily apparent. When a fallacy is used to deceive others, it is called 'sophistry,'" It is important that the student should understand the nature of the fallacy and understand its most common forms. As Jevons says: "In learning how to do right it is always desirable to be informed as to the ways in which we are likely to go wrong. In describing to a man the road which he should follow, we ought to tell him not only the turnings which he is to take but also the turnings which he is to avoid. Similarly, it is a useful part of logic which teaches us the ways and turnings by which people most commonly go astray in reasoning." In presenting the following brief statement regarding the more common forms of fallacy, we omit so far as possible the technical details which belong to text-books on logic. FALLACIES. I. _True Collective but False Particular._--An example of this fallacy is found in the argument that because the French race, collectively, are excitable, therefore a particular Frenchman must be excitable. Or that because the Jewish race, collectively, are good business people, therefore the particular Jew must be a good business man. This is as fallacious as arguing that because a man may drown in the ocean he should avoid the bath, basin, or cup of water. There is a vast difference between the whole of a thing and its separate parts. Nitric acid and glycerin, separately, are not explosive, but, combined, they form nitro-glycerin, a most dangerous and powerful explosive. Reversing this form of illustration, we remind you of the old saying: "Salt is a good thing; but one doesn't want to be put in pickle." II. _Irrelevant Conclusion._--This fallacy consists in introducing in the conclusion matter not contained in the premises, or in the confusing of the issue. For instance: (1) All men are sinful; (2) John Smith is a man; therefore (3) John Smith is a horse thief. This may sound absurd, but many arguments are as fallacious as this, and for the same reason. Or another and more subtle form: (1) All thieves are liars; (2) John Smith is a liar; therefore (3) John Smith is a thief. The first example arises from the introduction of new matter, and the last from the confusion of the issue. III. _False Cause._--This fallacy consists in attributing cause to a thing which is merely coincident with, or precedent to, the effect. For instance: (1) The cock crows just before or at the moment of sunrise; therefore (2) the cock-crowing is the cause of the sunrise. Or, again: (1) Bad crops followed the election of a Whig president; therefore (2) the Whig party is the cause of the bad crops. Or, again: (1) Where civilization is the highest, there we find the greatest number of high hats; therefore (2) high hats are the cause of civilization.