While humanities may be very useful as part of an undergraduate education, I am not sure what major role it will play in the education of a doctoral student in science and engineering unless the department is at a world class level in terms of research. A humanities department with one faculty each in history, english, economics and sociology will not become world class due to the lack of a critical mass. Instead, it may be better to open a department with focus on subjects like anthropology or archeology and recruit ten world class faculty in this area. Of course, getting faculty will be a problem even though many people believe that the very mention of IISc opening such a department will make the faculty working at other institutions to leave their institution and join IISc.
Instead of becoming all-rounders, shouldn't IISc focus on doing better on something that we already do reasonably well ? Regarding the comment that the IITs have humanities department, IISc should not be compared with IITs but with IIMs, which also offer only post-graduate education. Maybe IISc should open a humanities department as soon as IIM-Ahmedabad opens a chemistry department !