Skip to product information
1 of 12
Regular price €29.99 EUR
Regular price €29.00 EUR Sale price €29.99 EUR
Sale Sold out

Pythagoras cup, Greedy Cup, Cup of Justice, Tantalus cup or i koupa tis dikaiosynis Fair Cup 7.5CM

Pythagoras cup, Greedy Cup, Cup of Justice, Tantalus cup or i koupa tis dikaiosynis Fair Cup 7.5CM

Selling fast! Only 4 left.

Sustainable Handmade

Our materials are ethically sourced,under environmental
guidelines and practices.
There is no use of plastic-based materials such as acrylic. Ceramic, Bamboo, and Stainless steel are all sustainable, renewable materials that pass our sustainability check!

There is no opening at the top of the pot and the water is filled from a flower-shaped hole at the bottom.

Read more

Pythagoras cup, Greedy Cup, Cup of Justice

Get the Complet set with the Assassin's teapot

The story about this mysterious cup!

Cross-section of a Pythagorean cup being filled: at B, it is possible to drink all the liquid in the cup; but at C, the siphoning effect causes the cup to drain.

 mystery bottom-filling teapot made in Yaozhou, which was known historically as the blue-glazed ceramic capital of the Ancient Tang and Song Dynasties.
The mystery bottom-filling teapot was an imitation of the teapot from the Northern Song Dynasty (now housed as a National-Treasure Designated Collection in Shaanxi Provincial Museum in Xian, China).

The magic "Justice" cup has a dragon head in the middle with mouth and bottom openings. The cup can only hold a certain amount of water. If one pours too much water, then all the water in the cup would be drained through the dragon bottom opening.


The legend has it that The Tang Emperor presented the cup to his newly-wed prince and princess as a cautionary tale that one who is too greedy could instead lose all he possesses. The set also includes a "Jue", a reproduction of a Shang Dynasty (ca. 1200 BC) wine-drinking vessel.

justice cup

This teapot set can be used as either a decorative display or a working teapot set with magic and mysterious properties and a legend to tell.


There is also a different story about this mysterious cup
A Pythagorean cup is a form of drinking cup which is a deep sense of control measures of a drink.

Creating a bowl ranked among the discoveries of Pythagoras of Samos.


The uniqueness of the bowl of Pythagoras is a fairly simple principle that works as a mechanism of the valve filling the cup up to a certain level you can drink its contents as a regular cup but that’s as soon as we overfill the liquid over the mark level of the cup all of its contents follows through a hole located at bottom of the bowl.


"Tradition says Pythagoras, during water supply, works in Samos around 530 BC moderated the workers' wine drinking by inventing the 'fair cup'.

When the wine surpasses the line, the cup totally empties, so the greedy one is punished.

View full details

Customer Reviews

Based on 4 reviews
Ken K.
Great and unique gift

This is a great and very unusual gift. It is not just a gag gift or drippy cup, but a beautifully made cup that can be used in everyday life. Now, just because it is an excellent example of a Pythagorean theorem is an added bonus. Buy this cup both for its beauty and its uniqueness.

Everything exceeded expectations!

Absolutely loved the cups!!! Delivered early. Quality and the colors were awesome. Couldn’t be more pleased.

Karl b.
Works great

Very cool and well crafted. Works great and is a fun gift for plumbers or mathematicians alike.

Superb gift to a Math-Science person, was well appreciated

Arrived quickly and in great condition. Cups worked as expected. The artwork on these is also very nice. It is a good conversation piece but may not be particularly useful for casual use as it is intended to displace its contents. Even to demo it, you have to carry something to catch the liquid.
However, this cup is a tribute to this great scientist-inventor-philosopher who is currently known only as the "Square-of-the-hypotenuse" guy. Pythogaurus is supposed to have urged moderation in eating meat and suggested not to get carried away by religious dictates. He influenced Aristotle who in turn would play a major role for both Socrates and Plato. This cup, according to the story, is about reinforcing fairness: His students, after doing their daily fieldwork, would rush back to drink wine and the first ones to arrive would drink more than their fair share leaving none for the later arrivals. Pythogaurus designed this cup so that an automatic siphon is created if the cup is overfilled, and all the contents get drained out.

  • Live Customers support

    We're here to help you with your issue or question. Just contact us now and one of our customer service representatives will be happy to assist!

  • Free Fast Shipping

    We do offer Free Shipping (Home to Home Delivery) on all products to worldwide. Free Shipping takes 8-12 days on average for US, CA, UK, EU, AU.

  • 7 Days Money Back

    If the products with any problems, no worries, we do offer 7 Days Money Back from the date you have received it or sent you the replacement instantly.

1 of 3