There is a summary on wikipedia of We Have Never Been Modern which says
Latour viewed modernism as an era that believed it had annulled the entire past in its wake.[29] He presented the antimodern reaction as defending such entities as spirit, rationality, liberty, society, God, or even the past.[30] Postmoderns, according to Latour, also accepted the modernistic abstractions as if they were real.[31] In contrast, the nonmodern approach reestablished symmetry between science and technology on the one hand and society on the other.
I can understand the antimodern position. I can take a guess about the modern position and post modern position. However, the nonmodern approach is not clear to me at all. The symmetry between science and society? I understand he drew connections between the science and society (Laboratory Life I think?), but the contrasts between the above positions are not really clear to me.