A few pages further on in this lecture by Rudolf Steiner we find:

‘In other words, the human being in general today has not yet come to pour the reality, which he experiences as an independent reality in his sleep, into the thoughts of the waking life, through willpower during the waking life. If one wants to become an anthroposophist in such a way that one receives the anthroposophical thoughts and then not simply passively surrenders to them, but by a strong will pours into the thoughts, into the pure thoughts of anthroposophy that which one is in dreamless sleep during every night, then one has climbed the first step of that which today one is entitled to call clairvoyance, then one lives clairvoyantly in the thoughts of anthroposophy. One reads a book with the strong will that one not only carries one’s daily life into the anthroposophical book, that one does not read so: a part the day before yesterday, then it stops, yesterday, then it stops, today, then it stops etc. People today read only with one of their pieces of life, namely only with their daily lives. Of course you can read Gustav Freytag like that, you can read Dickens like that, Emerson can be read like that, but not an anthroposophical book. When you read an anthroposophical book, you have to go into it with your whole person, and because you are unconscious in your sleep, so you have no thoughts – but the will lasts on – you have to go into it with the will. If you really put your will into that which lies in the words of a real anthroposophical book, you will at least become clairvoyant in your thoughts immediately through this will. And this will, it still has to go into those who represent our anthroposophy! If this will is driven like lightning into those who represent our anthroposophy, then anthroposophy can be represented before the world in the right way. It does not require any magic arts, but the energetic will, which not only carries the daily lifepieces into a book. Today, by the way, people no longer even read works with this complete lifepiece, but today, when reading newspapers, it is enough to make a few minutes of the day active in order to acquire what one has there. You don’t even have to be awake all day. But when one dives with all one’s human being into a book that comes from anthroposophy, then it becomes alive in one.’

The I in thinking by Mieke Mosmuller