Page:Mind (New Series) Volume 6.djvu/233

 ON THE NATURE OF THE NOTION OF EXTERNALITY. 217 purposely directs his ship to our island by means of the appropriate observations as to position, etc. (i.e., by means of taking the physical conditions into account), his mental states are not the essential determining factors in the case. The psychical states only enter into the result as enabling him to fulfil, in the body, the appropriate external condi- tions : for, as we have seen in the case of the shipwrecked sailor, those states can be dispensed with, provided that these conditions are fulfilled. To this last assertion it may be objected that we have here virtually acknowledged : " that though these mental factors are not the indispensable means of arriving at the given result, yet, if at any time we could exactly repeat the initial experiences, together with the appropriate volitions, the final result would be the same. In other words, if we, so to speak, put ourselves in the perceptual track of any causal sequence, we can follow it up to any point we like : so that there is a routine of mental phenomena, so far as that particular result is concerned." This, however, is not so ; the chief reason being provided by the fact that " in actuality no single strand of the causal web can be completely isolated from all the rest " (p. 210) - 1 It continually happens that we do repeat all the appro- priate conditions so far as these enter into consciousness, and yet the result miscarries owing not to any difference in any of the circumstances that enter into our conscious- ness at the outset, but, as would be the case supposing our navigator's instruments were to go wrong, to some change which has to be interpreted in terms of an external world. To vary our example in a way which may perhaps bring out this point even more clearly : We embark on board ship, but, instead of reaching our destination as on a pre- vious occasion, are wrecked upon a hidden reef which has come near the surface since our last voyage. Thus the primary conditions determining the perception of material objects and events, have themselves to be regarded as ex- ternal. This fact of having to comply with external conditions, and of having to adapt our conduct in accordance with what we take to be changes in those conditions, if we wish to attain any result in the material world, is, indeed, the 1 It is also to be noticed that the volitions must be based on, and in a sense express, beliefs concerning the physical world as such : and in seeking the origin of these beliefs, whether with regard to their general or their special features, we are forced back on experiences which volition has had no direct share in bringing about.