Atrocities against Dalits have been in sharp focus this week - a reminder of how in 21st century India, we still treat people as lesser human beings because of their caste. How relevant is caste in today's India? Meira Kumar, former Lok Sabha Speaker; Narendra Jadhav, Rajya Sabha MP; Udit Raj, Leader, BJP; and Professor Vimal Thorat, Convenor, National Campaign on Dalit Human Rights, share their views.