others, not considering what is possible for man to know, and what is impossible, and therefore striving to attain to a knowledge of the unknowable.”[158] This application of sensuous images to what has a certain similarity to them, is pronounced to be the basis and the knowledge of the cause, because, in his opinion, a transference such as this cannot be corroborated by the testimony of mere immediate sensation; thus the Stoic method of seeking a basis in thought is excluded, and in this respect the mode of explanation adopted by Epicurus is directly opposed to that of the Stoics. One circumstance which strikes us at once in Epicurus is the lack of observation and experience with regard to the mutual relations of bodies: but the kernel of the matter, the principle, is nothing else than the principle of modern physics. This method of Epicurus has been attacked and derided, but on this score no one need be ashamed of or fight shy of it, if he is a physicist; for what Epicurus says is not a whit worse than what the moderns assert. Indeed, in the case of Epicurus the satisfactory assurance is likewise always present of his emphasizing the fact most strongly that just because the evidence of the senses is found to be lacking, we must not take our stand on any one analogy. Elsewhere he in the same way makes light of analogy, and when one person accepts this possibility and another that other possibility, he admires the cleverness of the second and troubles himself little about the explanation given by the first; it may be so, or it may not be so.[159] This is a method devoid of reason, which reaches no further than to general conceptions. Nevertheless, if Physical Science is considered to relate to immediate experience on the one hand, and, on the other hand—in respect of that which cannot be immediately experienced—to relate to the application of the above according to a resemblance existing between it and that which is not matter of experience, in that case Epicurus may well be looked on as the chief promoter, if not the originator of this method, and also as having asserted that it is identical with knowledge. Of the Epicurean method in philosophy we may say this, that it likewise has a side on which it possesses value, and we may in some measure assent when we hear, as we frequently do, the Epicurean physics favourably spoken of. Aristotle and the earlier philosophers took their start in natural philosophy from universal thought _a priori_, and from this developed the Notion; this is the one side. The other side, which is just as necessary, demands that experience should be worked up into universality, that laws should be found out; that is to say, that the result which follows from the abstract Idea should coincide with the general conception to which experience and observation have led up. The _a priori_ is with Aristotle, for instance, most excellent but not sufficient, because to it there is lacking connection with and relation