I mentioned earlier that it is typical of the sexual races that the flair for physical engineering is rather stronger than the instinct for communication. This was an observed but little-understood fact for many centuries; it was not till this phenomenon of dualism (and triadism for the three-sexed, etc.) was studied that the earlier observation was clarified. If you will consider briefly the various primitive sources of power and transport, you will realize that--outside of the psi-based techniques--most of these are involved with principles of symmetry and/or equivalence; these concepts are obvious to the two-sexed. On the other hand, the principle of unity, underlying all successful communication--physical, verbal, psial, or other--and which is also the basis for the application of psi to engineering problems--is for these species, in early stages, an almost mystical quality. As with most life-forms, the reproductive act is, among sexual beings, both physically pleasurable and biologically compulsive, so that it is early equated with religio-mystic sensations. Among sexual species, these attitudes are intensified by the communicative aspects of the act. (Cartoon-type diagrams here which frankly gave me to think a bit!) We have much to learn yet about the psychology of this phenomenon, but enough has been established to make clear that the concept of unity for these races is initially almost entirely related to the use of their sexuality, and is later extended to other areas--religion and the arts of communication at first--with a mystical--indeed often reverent attitude! I hardly need to remind you that the tendencies I have been discussing are the primitive and underlying ones. Obviously, at the point of contact, any species must have acquired at least enough sophistication in the field of physics--quanta, unified field theory, and atomic transmutation for a start--to have begun to look away from the essentially blind alley of dualistic thinking. But the extent to which these Terrans were still limited by their early developmental pattern is indicated by the almost unbelievable fact that they developed ultra-dimensional transport _before_ discovering any more effective channels of communication than the electromagnetic! Thus their first contacts with older civilizations were physical; and, limited as they still are almost entirely to aural and visual communication, they were actually unable to perceive their very first contact on Aldebaran VI. * * * * *