At this point, you have probably struggled enough with teh summary and may be wondering just how well you have done. It's a tough call, no matter the text being summarized. To help, here is the summary I have come up with. Yours need not match mine, but this is a good guide. I won't bother with attributing the material to Mill, which is something you need to do.

It's an age old question how much power society should have over individuals. When rulers and individuals had an atagonistic relationship, notions of liberty concerned protecting the individual from abuse by the rulers even though these rulers were to protect the weak. To protect from abuse, rights were promoted and constitutional protections were instituted. Over time, the concerns of the rulers came to align themselves with the concerns of the ruled and rulers also came to serve at the pleasure of the ruled. From this the will of the people evolved to the will of the majority which in turn has become something of a tyranny of the majority, which is what we must now guard against. This social tyranny is more difficult to escape than is political tyranny. There is a need to limit even legitimate encroachment of these rights. Social tyranny often is the result custom, something doesn't get questioned as it should. Custom is usually the views and attitudes of the ruling classes passed on to those who are ruled and in this way custom trumps reason. Similarly, only once no religion was able to dominate did we get religious freedom. This toleration is limited and applies to the way governments are tolerated, but based on each individual's personal prefernces. Some want interference in situatiosn where others want none. It must be that government and society should interfere with an indivudal only to prevent harm. This applies only to the sound of mind and body because some need to be guided more directly. Preventing harm can require people to be compelled to act, such as by testifying against a criminal. Similarly, we must have liberty of thought and association if we are to be free, particualarly when it comes to the temporal and the spiritual. Liberty of thought underpins all liberties.