The WTS has constantly been changing its foundations.
They presented "proof" that Jesus was invisibly present since 1874.
Then they decided that he wasn't present until 1914.
The Great Pyramid was God's stone witness.
Its measurements proved the 1874 date.
Then its measurements changed to prove the 1914 date.
Then the Great Pyramid was Satan's stone witness, so its measurements proved nothing.
They said that Russell was the faithful and wise servant.
Then they said that they never said it.
Then they said that the faithful and discreet slave was the "anointed" on earth.
Now it's just the GB acting as the faithful and discreet slave.
The end was coming in 1914, 1925, 1942, 1975, any day now.
The list goes on and on.
Despite all these changes, whatever they teach at any given moment is "the truth."