“In the absence of any other proof, the thumb alone would convince me of God’s existence.”
—Isaac Newton
The human hand contains fifty-four bones—about a quarter of all the bones in the body. We sometimes describe something small as “palm-sized,” yet within that small space lies an astonishing concentration of bones and joints. This intricate structure gives the hand remarkable flexibility, enabling us to perform an extraordinary range of precise and delicate movements.
At the center of this design is the thumb. Shorter and thicker than the other fingers, it stands apart in both form and function. While the four fingers bend in the same direction, the thumb moves from a different position and at a different angle. The four fingers each contain three bones, but the thumb has only two—and thanks to its unique joint with the first metacarpal, it can reach across to touch the fingertips. This movement, known as opposition, allows us to grip objects firmly or pick up the most delicate items, such as a strand of hair. It is this very motion that enables humans to use tools and carry out countless tasks.
Primates such as chimpanzees and monkeys also have five digits, yet none can achieve the complete opposition unique to humans. The simple fact that our thumbs can touch the tips of our fingers is a marvel that continues to inspire even scientists today.
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