What should I research in Modern Philosophy?

So I have to do research on a topic concerning Modern Philosophy. I feel like Socrates as a midwife; I can evaluate ideas and bring them to fruition but can't come up with any of my own. This is where you may help. What are some topics concerning the big Modernists (Descartes, Locke, Hume, Spinoza) that I can research? It can deal with just one or more of them. Thanks. Help is always appreciated.What should I research in Modern Philosophy?
Altruism has only been a subject since the 19th century, when Comte (1798-1857) coined the word. "As such it defines a theory of conduct by which only actions having for their object the happiness of others possess a moral value." http://www.newadvent.org/cathen/01369a.h鈥?/a>

Selfishness has only been a topic since the 20th century.
http://en.wikipedia.org/wiki/The_Virtue_鈥?/a>

Social justice has only been a topic in the last 50 years.

If you want Locke, start with his quote: "The state of nature has a law of nature to govern it, which obliges every one: and reason, which is that law, teaches all mankind, who will but consult it, that being all equal and independent, no one ought to harm another in his life, health, liberty, or possessions..." http://www.constitution.org/jl/2ndtr02.h鈥?/a> This is the entire basis, as seen by America's Founders, for the democratic republic they created, but specifically for the Ninth and Tenth Amendments.

Or he gave the modern idea of the tabula rasa mind. http://aynrandlexicon.com/lexicon/tabula鈥?/a>What should I research in Modern Philosophy?
research George Carlin. man was as modern philosophy as you can get.