Dukas ali ndi akatswiri opanga uinjiniya wamakina, gulu la ogwira ntchito odziwa zambiri komanso gulu loyang'anira akatswiri.Lingaliro lopanga limayang'ana kwambiri pakupulumutsa mphamvu ndipo likudzipereka kuti likhale langwiro ndikuwongolera njira zamakono kuti apeze ukadaulo wapamwamba kwambiri wopulumutsa mphamvu pafupipafupi, kukwaniritsa mawonekedwe osalankhula, kukhazikika, kupulumutsa mphamvu ndi chitetezo.