" He who would make proposals as to the future must not content himself with a knowledge of life that merely touches life's surface: he must investigate its depths. Life in its entirety is like a plant. The plant contains not only what it offers to external life; it also holds a future state within its hidden depths. One who has before him a plant only just in leaf, knows very well that after some time there will be flowers and fruit also on the leaf-bearing stem. In its hidden depths the plant already contains the flowers and fruit in embryo; yet by mere investigation of what the plant now offers to external vision, how should one ever tell what these new organs will look like? This can only be told by one who has learnt to know the very nature and being of the plant.
So, too, the whole of human life contains within it the germs of its own future; but if we are to tell anything about this future, we must first penetrate into the hidden nature of the human being. And this our age is little inclined to do. It concerns itself with the things that appear on the surface, and thinks it is treading on unsafe ground if called upon to penetrate to what escapes external observation. In the case of the plant the matter is certainly more simple. We know that others like it have again and again borne fruit before. Human life is present only once; the flowers it will bear in the future have never yet been there. Yet they are present within man in the embryo, even as the flowers are present in a plant that is still only in leaf. And there is a possibility of saying something about man's future, if once we penetrate beneath the surface of human nature to its real essence and being. It is only when fertilised by this deep penetration into human life, that the various ideas of reform ...can become fruitful and practical."
"Now man possesses a fourth member of his being; and this fourth member he shares with no other earthly creature. It is the vehicle of the human ‘ I ,’ of the human Ego. The little word ‘ I ’ - as used, for example, in the English language - is a name essentially different from all other names. To anyone who ponders rightly on the nature of this name, there is opened up at once a way of approach to a perception of man's real nature. All other names can be applied, by all men equally, to the thing they designate. Everyone can call a table ‘table,’ and everyone can call a chair ‘chair’; but it is not so with the name ‘ I .’ No one can use this name to designate another. Each human being can only call himself ‘ I ’; the name ‘ I ’ can never reach my ear as a designation of myself. In designating himself as ‘ I ,’ man has to name himself within himself. A being who can say ‘ I ’ to himself is a world in himself. Those religions which are founded on spiritual knowledge have always had a feeling for this truth. Hence they have said: With the ‘ I ,’ the ‘God’ - who in the lower creatures reveals himself only from without, in the phenomena of the surrounding world - begins to speak from within. The vehicle of this faculty of saying ‘ I ,’ of the Ego-faculty, is the ‘Body of the Ego,’ the fourth member of the human being."
What Steiner is saying is that whilst the concept or principle of a plant is apparent and present in every example of the sort, each human being is a concept or principle in himself and this is separate from his adherence to the general concept of a human being. In contrast to the idea of an omnipotent and external force (or God) acting upon him, each man who has come to know his real nature has the power over himself and the ability to guide his own actions.