What is ijtihad, and why did Iqbal call it the principle of movement in Islam?
In court I know ijtihad in its narrow legal sense: independent reasoning by a qualified jurist to derive a ruling where texts are silent or unclear. But Iqbal, in the sixth lecture of the Reconstruction, "The Principle of Movement in the Structure of Islam", makes it something much broader, almost a philosophy of history.
Could someone explain the classical background and what exactly Iqbal does with it? In particular, what did he propose about who should exercise ijtihad today?