Discovering Isaiah Berlin - Henry Hardy (Long Version) - Johnny Lyons
Brief introduction to Isaiah Berlin
Please see a brief introduction of Isaiah Berlin from Wikipedia.
Two Concepts of Liberty
An Important idea of Isaiah Berlin is the "Two Concepts of Liberty".
The following articles provide introductions to the two concepts of liberty.
Wikipedia - Two concepts of libertyStanford Encyclopedia of Philosophy - Positive and Negative Liberty
The full text of the lecture "Two Concepts of Liberty" can be found here.
Value Pluralism
Value Pluralism is another important idea of Isaiah Berlin. The following are articles from Wikipedia and Stanford Encyclopedia of Philosophy.