It is the task of Theological Encyclopedia to investigate the nature of Theology for the stated purposes of understanding it, of passing criticism upon its progress, and of assisting its healthful development. It is not sufficient that it answer the question, What Theology is; it must also critically examine the studies that have thus far been bestowed upon Theology, and mark out the course henceforth to be pursued. This investigation would bear no scientific character, and consequently would not be Encyclopedic, if Theology were merely a private pursuit of individuals. Now, however, it is both, because Theology presents an interest that engages the human mind as such. We face a phenomenon that extends across the ages, and has engaged many persons, and therefore cannot be the outcome of a whim of notion, nor yet of an agreement or common contract, but is governed by a motive of its own, which has worked upon these persons in all ages. This motive cannot lie elsewhere than in the human mind; and if a certain regularity, order and perceptible development are clearly manifest in these theological studies, as prosecuted in whatever period and by whatever persons, it follows that this motive, by which the human mind is impelled to theological investigation, not only formally demands such an investigation, but is bound to govern the content and the tendency of these studies. Distinction therefore must be made between the theological study of individual theologians and the impulse of Theology which they obeyed consciously or unconsciously, entirely or in part. This theological impulse is the general phenomenon, which is certainly exhibited in special theological studies, but never exhausts itself in them. This general phenomenon lies behind and above its temporal and individual revelations. It is not the excogitation of an individual man, but men have found it in the human mind. Neither was it found as an indifferent something, but as something definite in essence and tendency; in virtue of which it can and must be included in the investigation of science as a whole. This very distinction, however, between the theological motive in general and the effect of this motive upon the individual theologian, presents both the danger and the probability that the study of Theology will encounter influences that are antagonistic to this motive; which divergence will of necessity cause it to become bastardized and the mutual relation of these studies to suffer loss. With this motive itself, therefore, the impulse of criticism is given, and the scientific investigation into the essence of Theology would never be finished, if it did not inquire as to how far this motive had been allowed to exert itself, and in what way it is to continue its task.

Technically, therefore, encyclopedical investigation would be prosecuted most accurately if the essence of Theology could first be determined thetically; if, after that, empirical Theology could be compared with this; and if the means could be indicated therapeutically by which to make and maintain the healthful development of Theology. But to follow out this scheme would be unwise for three reasons. In the first place, the thetic result cannot be found except in consultation with empiricism, and this calls in the aid of the deviations as antitheses for the definition of the conception. In tie second place, with Theology in general, and afterwards ffith each of its parts, a continuous repetition of consonant criticism could not be avoided. And in the third place, the thetical, critical and therapeutical or dietetical treatment of each department would be torn altogether out of relation and come in order at three entirely different places. This necessitates the sacrifice of technical accuracy to the demands of a practical treatment; and the arrangement of the division of the investigation in the order of importance. Hence in this Encyclopedia also the real investigation divides itself into two parts, the first of which deals with Theology as such, while the second reviews her subdivisions. And the end of each aim is: to understand Theology as such, and her parts, organically. Encyclopedia may not rest until it has grasped Theology as an organic part of general science, and has examined the departments of exegesis, church history, etc., as organic parts of the science of Theology.

If all investigators were fully agreed among themselves as to the nature and the conception of science, we could at once start out from this fixed datum and indicate what place Theology occupies in the sphere of science, and press the claims she ought to satisfy. But this is not the case. Not only is the conception of science very uncertain, but the very relation sustained by the several thinkers to Theology and its object exercises frequently a preponderating influence upon the definition of the conception of science. There can be no clearness, therefore, in an encyclopedical exposition until it is definitely stated what the writer understands by science and by its prosecution in general. And for this reason this investigation into the nature of Theology begins with a summary treatment of science and its prosecution. The organism of science itself must be clearly outlined, before the place which Theology occupies in it can be determined.