It therefore treats of understanding without any regard to difference in the objects to which the understanding may be directed. The logic of the special employment of the understanding contains the rules of correct thinking as regards a certain kind of objects. The former may be called the logic of elements, the latter the organon of this or that science. The latter is commonly taught in the schools as a propaedeutic to the sciences, though, according to the actual procedure of human reason, it is what is obtained last of all, when the particular science under question has been already brought to such completion that it requires only a few finishing touches to correct and perfect it. For the objects under consideration must already be known fairly completely before it can be possible to prescribe the rules according to which a science of them is to be obtained.
General logic is either pure or applied.
In the former we abstract from all empirical conditions under which our understanding is exercised, i.e. from the influence of the senses, the play of imagination, the laws of memory, the force of habit, inclination, etc. , and so from all sources of prejudice, indeed from all causes from which this or that knowledge may arise or seem to arise. For they concern the understanding only in so far as it is being employed under certain circumstances, and to become acquainted with these circumstances experience is required. Pure general logic has to do, therefore, only with principles a priori , and is a canon of understanding and of reason, but only in respect of what is formal in their employment, be the content what it may, empirical or transcendental. General logic is called applied, when it is directed to the rules of the employment of understanding under the subjective empirical conditions dealt with by psychology. Applied logic has therefore empirical principles, although it is still indeed in so far general that it refers to the employment of the understanding without regard to difference in the objects.