Who wrote the following saying the rung of a ladder was never meant to rest upon but only to hold ones foot long enough to enable them to put the other foot higher?

The saying, "the rung of a ladder was never meant to rest upon but only to hold one's foot long enough to enable them to put the other foot higher," is attributed to Thomas Henry Huxley. Huxley was a prominent English biologist and anthropologist in the 19th century, known for his advocacy of Darwin's theory of evolution. This metaphor emphasizes the idea of progress and the importance of striving for higher goals rather than becoming complacent.