To render intelligible that part of the story of my life, which refers to my sentiments regarding religion, I must first give in advance a short practical history of the Jewish religion, and at the outset say something of the idea of religion in general, as well as of the difference between natural and positive religion.
Religion in general is the expression of gratitude, reverence and the other feelings, which arise from the dependence of our weal and woe on one or more powers to us unknown. If we look to the expression of these feelings in general, without regard to the particular mode of the expression, religion is certainly natural to man. He observes many effects which are of interest to him, but whose causes are to him unknown; and he finds himself compelled, by the universally recognised Principle of Sufficient Reason, to suppose these causes, and to express towards them the feelings mentioned.
This expression may be of two kinds, in conformity either with the imagination or with reason. For either man imagines the causes to be analogous to the effects, and ascribes to them in themselves such attributes as are revealed through the effects, or he thinks them merely as causes of certain effects, without seeking thereby to determine their attributes in themselves. These two modes are both natural to man, the former being in accordance with his earlier condition, the latter with that of his perfection.
The difference between these two modes of representation has as its consequence another difference of religions. The first mode of representation, in accordance with which the causes are supposed to be similar to the effects, is the mother of polytheism or heathenism. But the second is the basis of true religion. For as the kinds of effects are different, the causes also, if held to be like them, must be represented as different from one another. On the other hand, if, in accordance with truth, we conceive the idea of cause in general for these effects, without seeking to determine this cause, either in itself (since it is wholly unknown), or analogically by help of the imagination, then we have no ground for supposing several causes, but require to assume merely a single subject, wholly unknown, as cause of all these effects.
The different philosophical systems of theology are nothing but detailed developments of these different modes of representation. The atheistic system of theology, if so it may be called, rejects altogether this idea of a first cause, (as, according to the critical system at least, it is merely of regulative use as a necessary idea of reason). All effects are referred to particular known or unknown causes. In this there cannot be assumed even a connection between the various effects, else the reason of this connection would require to be sought beyond the connection itself.
The Spinozistic system, on the contrary, supposes one and the same substance as immediate cause of all various effects, which must be regarded as predicates of one and the same subject. Matter and mind are, with Spinoza, one and the same substance, which appears, now under the former, now under the latter attribute. This single substance is, according to him, not only the sole being that can be self-dependent, that is, independent of any external cause, but also the sole self-subsistent being, all so-called beings besides it being merely its modes, that is, particular limitations of its attributes. Every particular effect in nature is referred by him, not to its proximate cause (which is merely a mode), but immediately to this first cause, which is the common substance of all beings.
In this system unity is real, but multiplicity is merely ideal. In the atheistic system it is the opposite. Multiplicity is real, being founded on the nature of things themselves. On the other hand, the unity, which is observed in the order and regularity of nature, is merely an accident, by which we are accustomed to determine our arbitrary system for the sake of knowledge. It is inconceivable therefore how any one can make out the Spinozistic system to be atheistic, since the two systems are diametrically opposed to one another. In the latter the existence of God is denied, but in the former the existence of the world. Spinoza's ought therefore to be called rather the acosmic system.
The Leibnitzian system holds the mean between the two preceding. In it all particular effects are referred immediately to particular causes; but these various effects are thought as connected in a single system, and the cause of this connection is sought in a being beyond itself.
Positive religion is distinguished from natural in the very same way as the positive laws of a state from natural laws. The latter are those which rest on a self-acquired, indistinct knowledge, and are not duly defined in regard to their application, while the former rest on a distinct knowledge received from others, and are completely defined in regard to their application.
A positive religion however must be carefully distinguished from a political religion. The former has for its end merely the correction and accurate definition of knowledge, that is, instruction regarding the first cause: and the knowledge is communicated to another, according to the measure of his capacity, just as it has been received. But the latter has for its end mainly the welfare of the state. Knowledge is therefore communicated, not just as it has been received, but only in so far as it is found serviceable to this end. Politics, merely as politics, requires to concern itself about true religion as little as about true morality. The injury, that might arise from this, can be prevented by other means which influence men at the same time, and thus all can be kept in equilibrium. Every political religion is therefore at the same time positive, but every positive religion is not also political.