But in the study of Logic we have possibly the best exercise in the development and culture of this particular faculty. As Brooks well says: "The study of Logic will aid in the development of the power of deductive reasoning. It does this first by showing the method by which we reason. To know how we reason, to see the laws which govern the reasoning process, to analyze the syllogism and see its conformity to the laws of thought, is not only an exercise of reasoning, but gives that knowledge of the process that will be both a stimulus and a guide to thought. No one can trace the principles and processes of thought without receiving thereby an impetus to thought. In the second place, the study of logic is probably even more valuable because it gives practice in deductive thinking. This, perhaps, is its principal value, since _the mind reasons instinctively without knowing how it reasons_. One can think without the knowledge of the science of thinking, just as one can use language correctly without a knowledge of grammar; yet as the study of grammar improves one's speech, so the study of logic cannot but improve one's thought." The study of the common _fallacies_, such as "Begging the Question," "Reasoning in a Circle," etc., is particularly important to the student, for when one realizes that such fallacies exist, and is able to detect and recognize them, he will avoid their use in framing his own arguments, and will be able to expose them when they appear in the arguments of others. The fallacy of "Begging the Question" consists in assuming as a proven fact something that has not been proven, or is not accepted as proven by the other party to the argument. It is a common trick in debate. The fact assumed may be either the particular point to be proved, or the premise necessary to prove it. Hyslop gives the following illustration of this fallacy: "_Good institutions should be united_; Church and State are good institutions; therefore, Church and State should be united." The above syllogism seems reasonable at first thought, but analysis will show that the major premise "Good institutions should be united" is a mere assumption without proof. Destroy this premise and the whole reasoning fails. Another form of fallacy, quite common, is that called "Reasoning in a Circle," which consists in assuming as proof of a proposition the proposition itself, as for instance, "This man is a rascal, _because he is a rogue_; he is a rogue, _because he is a rascal_." "We see through glass, _because it is transparent_." "The child is dumb, _because it has lost the power of speech_." "He is untruthful, _because he is a liar_." "The weather is warm, _because it is summer_; it is summer, _because the weather is warm_."