The Hi, I'm Peter Adamson, and you're listening to the History of Philosophy Podcast, brought to you with the support of the Philosophy Department at King's College London at the LMU in Munich, online at

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History of Philosophy.net. Today's episode, Get to the point, 14th century physics.

It's a bit misleading to talk about Aristotelian physics, not because Aristotle was uninterested in physics. To the contrary, he quite literally wrote the book on the subject.

Already in late antiquity and still in the medieval worlds of Islam by Zant, and Latin Christianity, his work, the physics, was the fundamental source for natural philosophy.

The word physics comes from the Greek fuses meaning nature.

What I mean is rather that in a way Aristotle had not one but two physics, one for the

terrestrial world and one for the heavens.

Down here in the region where we live, often called the sublunary realm because it is situated below the sphere of the moon,

all things are made of four elements, air, earth, fire, and water.

They have natural tendencies to move in straight lines up or down, that is to say,

away from or towards the center point of the universe. This is because they are trying to reach

what Aristotle calls their natural places.

Thus fire tries to occupy the region just below the sphere of the moon,

while Earth tries to work its way towards the center of the cosmos,

which is why flames flicker upwards and stones fall

downwards.

The reason that the four elements do not just sift apart is that they are bound together

as composite substances, something that Aristotelians across the ages

tended to explain with reference to heavenly movement. It is because the heavens revolve around us that our world is so complex

and varied. And revolve around us that our world is so complex and varied.

And revolve around us, they do.

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