transcendent nature, we must not shrink from a contradiction, and boldly say: the final cause is a motive which acts upon a being, by which it is not known. For certainly the termite nests are the motive which has produced the toothless muzzle of the ant‐bear, and also its long extensile, glutinous tongue: the hard egg‐shell which holds the chicken imprisoned is certainly the motive for the horny point with which its beak is provided in order to break through that shell, after which it throws it off as of no further use. And in the same way the laws of the reflection and refraction of light are the motive for the wonderfully ingenious and complex optical instrument, the human eye, which has the transparency of its cornea, the different density of its three humours, the form of its lens, the blackness of its choroid, the sensitiveness of its retina, the contracting power of its pupil, and its muscular system, accurately calculated according to those laws. But those motives acted before they were apprehended; it is not otherwise, however contradictory it may sound. For here is the transition of the physical into the metaphysical. But the latter we have already recognised in the _will_; therefore we must see that the will which extends an elephant’s trunk towards an object is the same will which has also called it forth and formed it, anticipating objects. It is in conformity with this that in the investigation of _organised_ nature we are entirely referred to _final causes_, everywhere seek for these and explain everything from them. The _efficient causes_, on the contrary, here assume only a quite subordinate position as the mere tools of the final causes, and, just as in the case of the voluntary movement of the limbs, which is confessedly effected by external motives, they are rather assumed than pointed out. In explaining the physiological _functions_ we certainly look about for the efficient causes, though for the most part in vain; but in explaining the origin of the parts we again look for them no more, but are satisfied with the final causes alone. At the most we have here some such general principle as that the larger the part is to be the stronger must be the artery that conducts blood to it; but of the actually efficient causes which bring about, for example, the eye, the ear, the brain, we know absolutely nothing. Indeed, even in explaining the mere functions the final cause is far more important and more to the point than the efficient; therefore, if the former alone is known we are instructed and satisfied with regard to the principal matter, while, on the other hand, the efficient cause alone helps us little. For example, if we really knew the _efficient cause_ of the circulation of the blood, as we do not, but still seek it, this would help us little unless we knew the final cause, that the blood must go into the lungs for the purpose of oxidation, and again flow back for the purpose of nourishing;