Academical logicians have a doctrine the reverse of this. They assert that their syllogisms yield conclusions that are always as certain as the premises. Grant their premises and you are obliged to accept their conclusions. This is so, because a regular syllogistic conclusion is simply a restating in other words of the information, or part of the information, already contained in the premises. If the syllogism has any use at all, it is merely as an aid to recollection; no new idea is generated by it. It is needless to insist on a fact so notorious as that ordinary rational conclusions--those that form the staple of our daily thought--are not by any means so certain as the data from which they are drawn. For example, the sky is red and lowering this evening, and we conclude therefrom that the weather will be bad to-morrow. There is no doubt about the present aspect of the sky, but much doubt about the inference. The form of an act of reasoning or argumentation may be rendered plainer by a diagram. S A --- --- C _I_ --- --- S A represents the precedent. S is the Subject or body of the precedent; A (the _Applicate_) is one property, or a part, or a relation of S abstracted from the rest to illustrate a case. C is the case; _I_ is the conclusion (or inference). _I_ results from imagining C to be associated with a property or relation similar to A. The sum of our _I_'s constitutes what we know of the world and man before we were born, of what is taking place in other parts of the world or universe, of what may take place in the future, and of the concealed and inaccessible parts of present objects. This is true not only of the results of our own reasoning but of what we have learned as verified knowledge from others, for the interpretation of language is, in the last analysis, a rational conclusion. All the parts of an argument exist in the mind, but they are not always expressed in language. When treated dialectically the implicit members are expressed, and the terms arranged so as to show as clearly as possible the nature of the argument. The following are the points most necessary to be observed in constructing or analysing an argument. (1) C must resemble S, for that is the basis of the argument. If C is not felt to be like S, or (as sometimes happens) is explicitly declared to be unlike S, there can be no conclusion. The precedent is not applicable to the case. A may, or may not, be associated with S; that is to say, a verbal negation may appear in the statement of the relation of S to A, but there must be no negation with respect to the relation of C to S.