A distinction is commonly made between that which is immediately cognized and that which is inferred or concluded. That in a figure which is bounded by three straight lines there are three angles, is an immediate cognition; but that these angles are together equal to two right angles, is an inference or conclusion. Now, as we are constantly employing this mode of thought and have thus become quite accustomed to it, we no longer remark the above distinction, and, as in the case of the so-called deceptions of sense, consider as immediately perceived, what has really been inferred. In every reasoning or syllogism, there is a fundamental proposition, afterwards a second drawn from it, and finally the conclusion, which connects the truth in the first with the truth in the second- and that infallibly. If the judgement concluded is so contained in the first proposition that it can be deduced from it without the meditation of a third notion, the conclusion is called immediate (consequentia immediata); I prefer the term conclusion of the understanding. But if, in addition to the fundamental cognition, a second judgement is necessary for the production of the conclusion, it is called a conclusion of the reason. In the proposition: All men are mortal, are contained the propositions: Some men are mortal, Nothing that is not mortal is a man, and these are therefore immediate conclusions from the first. On the other hand, the proposition: all the learned are mortal, is not contained in the main proposition (for the conception of a learned man does not occur in it), and it can be deduced from the main proposition only by means of a mediating judgement.
In every syllogism I first cogitate a rule (the major) by means of the understanding. In the next place I subsume a cognition under the condition of the rule (and this is the minor) by means of the judgement. And finally I determine my cognition by means of the predicate of the rule (this is the conclusio), consequently, I determine it a priori by means of the reason. The relations, therefore, which the major proposition, as the rule, represents between a cognition and its condition, constitute the different kinds of syllogisms. These are just threefold- analogously with all judgements, in so far as they differ in the mode of expressing the relation of a cognition in the understanding- namely, categorical, hypothetical, and disjunctive.
When as often happens, the conclusion is a judgement which may follow from other given judgements, through which a perfectly different object is cogitated, I endeavour to discover in the understanding whether the assertion in this conclusion does not stand under certain conditions according to a general rule. If I find such a condition, and if the object mentioned in the conclusion can be subsumed under the given condition, then this conclusion follows from a rule which is also valid for other objects of cognition. From this we see that reason endeavours to subject the great variety of the cognitions of the understanding to the smallest possible number of principles (general conditions), and thus to produce in it the highest unity.