borromean-rings

Look at another form of the thing: you can play it not only by two as one, but you can play it by three as one. You know the trademark for Ballantine’s Ale, which is three interlocked rings. Now, the way these rings are interlocked is such that they are joined only if the three of them are present. If you take one away, the other two fall apart. This is a very interesting phenomenon, but it can be created physically, with steel rings. Their cohesion depends on all three of them being present.

~ Alan Watts: Breaking Through Negativity

Reference:

borromean-rings-1

borromean-rings-2-large