To take an example, the impressions of roundness, angularity, smoothness, roughness, colour, etc., of a table contain, all told, nothing that could assure us of the existence of the object 'table' as the real content of an external world. How, then, do we receive the conviction of the latter's existence? Reid's answer is, by entering into an immediate intuitive relationship with it. It is true that to establish this relationship we need the stimuli coming from the impressions which our mind receives through the various senses. Yet this must not induce us to confuse the two. When nature speaks to man through his senses, something occurs exactly analogous to the process when man communicates with man through the spoken word. In both cases the perception, that is, the result of the process of perception, is something quite other than the sum of sensations underlying it. Per-ceiving by means of the senses is none other than a re-ceiving of nature's language; and this language, just like human language, bears two entirely different elements within it. According as one or the other element prevails in man's intercourse with nature, this intercourse will be either 'natural' or 'artificial' - to use the terms by which Reid distinguished the two stages of human speech. Just as every human being must once have listened only to the pure sound of the spoken word on a wholly sentient level in order to acquire the faculty of speaking, so also, in order to learn nature's language, the soul must once have been totally surrendered to the pure impressions of the senses. And just as with time the spoken word becomes a symbol for that which is signified by it, the consciousness turning to the latter and neglecting the actual sound-content of the word, so also in its intercourse with nature the soul, with its growing interest in the thing signified, turns its attention more and more away from the actual experiences of the senses. From this it follows that a philosophy which seeks to do justice to man's whole being must not be satisfied with examining the given content of human consciousness, but must strive to observe the actual process to which this content owes its emergence. In practice this means that a philosopher who understands his task aright must strive to reawaken in himself a mode of experience which is naturally given to man in his early childhood. Reid expresses this in the Inquiry in the following way: 'When one is learning a language, he attends to the sounds, but when he is master of it, he attends only to the sense of what he would express. If this is the case, we must become as little children again, if we will be philosophers: we must overcome habits which have been gathering strength ever since we began to think; habits, the usefulness of which atones for the difficulty it creates for the philosopher in discovering the first principles of the human mind.'