“Nature” by Ralph Waldo Emerson focuses on transcendentalism, a belief system which encourages respect for nature. Emerson said people do not appreciate all nature has to offer and do not give anything back to it. He divides the essay into eight sections, each of which further explores the relationship between humans and nature. Available on Amazon for $5.95.

“Meditations” by Marcus Aurelius is a series of 12 books which focus on Stoic philosophy. Each book is centered around a different part of Aurelius’ life. One of the main themes of the books is that everything comes from nature and will eventually return to it. Another is that there is a clear order which exists in the world, and people must embrace rationality and clear-mindedness to be at peace with it. Available on Amazon for $1.00.

“The Art of War” by Sun Tzu.m is an essay which is made up of 13 chapters, each outlining a specific aspect of warfare. However, it is not only for military strategy and tactics. Its main focus is on leadership, whether that is in the classroom, in an office or in a war zone. Available on Amazon for $2.98.

“The Death of the Author” by Roland Barthes argues that the text of a work and the creator is not related. Instead of using information about the author to criticize a work, people should focus solely on what the words say. The writer is simply there to write, not to explain the work. Available here in PDF form.

“The Republic” by Plato is one of the most widely-known philosophical works. It focuses on the true meaning of justice and whether a just man is happier or more fulfilled than an unjust man. It is divided into 10 separate books, each focusing on different parts of Socrates’ journey. Available on Amazon for $8.54.