"Human computers" known as Mentats have been developed and perfected to replace the capacity for logical analysis lost through the prohibition of computers. Through specific training, they learn to enter a heightened mental state in which they can perform complex logical computations that are superior to those of the ancient thinking machines. The patriarchal Bene Tleilax, or Tleilaxu, are amoral merchants who traffic in biological and genetically engineered products such as artificial eyes, "twisted" Mentats, and gholas. Finally, the Ixians produce cutting-edge technology that seemingly complies with (but pushes the boundaries of) the prohibitions against thinking machines. The Ixians are very secretive, not only to protect their valuable hold on the industry but also to hide any methods or inventions that may breach the anti-thinking machine protocols.