OK - where to start.... Part of me wants to say "well, you just have to read "Theosophy" and "Occult Science" to understand this.... as if all of us who have read those books really "get" it!! And, of course that wouldn't be a particularly helpful or friendly thing to say anyway! So I won't say it....!!!
So... instead I will say that this has to do with the anthroposophical ideas around spiritual evolution and the relationships between the different Kingdoms on Earth. In other words, one can see that a difference between the Plant and Mineral worlds is that the former have
life processes (etheric bodies), growth and so on. Yet there is certainly a Mineral element in the Plant kingdom. Next we have the Animal Kingdom and the Plant Kingdom - a difference here is that the Animals have feelings and are sentient (astral body) - yet there are certainly Plant and Mineral elements in the Animal Kingdom. Finally we come to the Human Being - the Human Being has something that these others do not have - an "I" or Ego (this term is used somewhat differently in anthroposophy than in psychology). But, of course, the Human Being also has elements in common, sheaths as it were, from these other Kingdoms. (and this is all very abbreviated and simplified).
So all four kingdoms are related - and there is also a hierarchy in terms of growth, in terms of spiritual development - and in anthroposophical terms this doesn't stop at Man - it carries on into the realms of angelic beings - but we don't need to go into that here!!
Thus the Human Being can be seen, in one sense, as the culmination of the other Kingdoms, and most obviously (as they are the closest) of the Animal Kingdom.
Back to the Man & Animal block - and to some of what's in this Lecture - the point is that the Animals are one-sided, are specialists. The fleetness of foot of the deer, the courage of the horse, the sense of smell of the dog - no Human Being comes near to these abilities - but the Human has something of each - plus is an "I" and can therefore use these senses how s/he wishes, is not subject merely to the pull of instinct, as is generally the case with animals. A beautiful explanation of this comes in 5th grade - when one studies the myth of Prometheus and Epimetheus. The latter gave all the "goodies" away to the animals - bravery, thick fur, keen eyesight - only the dregs were left when Prometheus came to give out something to Man. So instead he went and stole Fire from the Gods... and then paid dearly for it. Well... what is fire? The Divine Spark, the Light within , the I. When one studies Man & Animal in 4th grade and brings this picture of the animals having these qualities and the Human having something more... and then tells that myth in 5th grade - well, I've seen the "wow" look come across children's faces when they have an experience like that... One does not point it out, one lets it dawn out of the child's own soul.
Back to the subject at hand... another important element here is that, according to Steiner, the role of the Human Being is to one day develop to being a Co-Creator - the Human Being is ultimately as bound up with the Destiny of the Earth as Her destiny is with his (ours). Last night I was reading an interview with Barry Lopez and was sad to read where he said that "the world has no interest in the triumph of Homo Sapiens"... He was putting this in the context of those fundamentalist Christians who have taken the word "domain" (as in "man will have dominion over the earth") to somehow mean domination, destruction, an uncaring attitude toward the Earth. And so I could understand what he was saying. But it was sad to me because, as an anthroposophist, I see this as stemming (in part) from an incorrect understanding of that term - the root of "domain" is house - and we don't want to destroy our house, we want to protect and steward it. Animals, plants even minerals are our Brothers and Sisters - we have them in us, and it is our role to take care of them. And Earth is our Mother, the wise Gaia-Sophia who teaches us and who responds to our actions, good and bad.