The cycle of lectures now being published for the first time in English has always presented some difficulties because of the two lectures on the Mexican Mysteries, which form an important part of it. In these lectures Rudolf Steiner provides some historical material that not only cannot be confirmed — like the prehistorical material given in Occult Science and elsewhere — but appears to be even contrary to what is available to conventional archaeologists and historians. In particular, there are two major areas where at first sight Steiner would seem to have been in error, and there appear also to be some errors in detail about the characteristics of some Mexican deities cited by name. It is certain therefore that critics of Rudolf Steiner will cite these anomalies and label them errors, in the process attempting to discredit the kind of spiritual investigation engaged in by him. To the best of my knowledge — which is admittedly not complete — in no other lectures given by Steiner at any time are there any comparable divergences from accepted historical fact. With regard to the other material taken from the Akasha Chronicle it must be said that much of it is startling and of very great interest. But this is impossible to check or confirm from the historical and archeological material available to us, but there is also nothing in the historical record that can be said to refute it.