Logic is intellectual self-defense against such assaults on reason and also a method of quality control for checking the validity of your own views. But beyond these very practical benefits, informal logic—the kind we apply in daily life—is the gateway to an elegant and fascinating branch of philosophy known as formal logic, which is philosophy’s equivalent to calculus. Formal logic is a breathtakingly versatile tool. Much like a Swiss army...

To truly understand the subject of death, you have to be able to define it. Here, discover how the definition of death exists on multiple levels and how each of these levels - the religious, biological, philosophical, cultural, legal, and political - determines when a living being becomes a dead one.

Should death be considered "bad"? Should we even bother fearing it? As you reflect on philosophical arguments by the ancient Epicurus (who thought death wasn't bad for the dead) and the modern Thomas Nagel (who believes we should fear death), you'll consider the possibility that both sides are right.

In the first of several lectures on how major world faiths approach death, the focus is on Judaism. From the importance of mourning and burial rites to the recent resurgence in American Jewish belief in an afterlife, go inside the evolving views on death and the afterlife in Jewish history.

Learn why quadratic equations have "quad" in their name, even though they don't involve anything to the 4th power. Then try increasingly challenging examples, finding the solutions by sketching a square. Finally, derive the quadratic formula, which you've been using all along without realizing it.

In this lecture on what Professor Berkson calls "an inescapable part of the human condition," unpack the feelings and behaviors of the grieving process. Topics include the evolutionary benefits of grief, the five stages of grief laid out by Elizabeth Kübler-Ross, and the three categories of grieving identified by psychologist George Bonanno.

The seven kings of Dynasty XII built pyramids, fostered great literature (often for political purposes), and consolidated power once again in the center.

Learn the 24 letters of the Greek alphabet using the restored classical pronunciation, recognizing that there was some variation in pronunciation in the ancient world. Practice the pairings of vowels called diphthongs, and sound out a selection of words that you will soon be reading in sentences.

Discover how emergency doctors use OLD CAAAR: a simple mnemonic to accurately- and quickly-pinpoint the location and characteristics of a patient's pains. Also, learn what happens when a doctor has to think fast and doesn't have the time to ask each of the OLD CAAAR questions.

Light propagates through space as a wave, but it exchanges its energy in the form of particles. You learn how Louis de Broglie showed that this weird wave-particle duality also applies to matter, and how Max Born inferred that this relationship makes quantum mechanics inherently probabilistic.