O speculators about perpetual motion, how many vain chimeras have you created in the like quest? Go and take your place with the seekers after gold.

Leonardo da Vinci repeatedly criticized the pursuit of perpetual motion in his scientific notes, treating it as a seductive but impossible problem. Writing in the late 15th to early 16th century, he investigated mechanics, gears, weights, and hydraulic devices with an engineer’s rigor, yet concluded that machines cannot produce work indefinitely without an external source of energy. In the same spirit, he mocked “inventors” who promised self-moving wheels and other perpetual-motion contrivances, likening them to alchemists and treasure-seekers chasing fantasies. The remark belongs to the polemical, aphoristic side of his notebooks, where he warns readers against wasting ingenuity on chimeras rather than on demonstrable, testable mechanics.

The quote is a rebuke to wishful thinking disguised as technical ingenuity. By calling perpetual-motion schemes “vain chimeras,” Leonardo frames them as imaginative monsters—products of desire rather than of nature. His comparison to “seekers after gold” targets the same psychological impulse: the hope of effortless, limitless gain (whether wealth or power) without proportional labor or lawful cause. Implicitly, the passage champions a disciplined empiricism: nature has constraints, and sound invention begins by understanding them, not by trying to outwit them. The line also shows Leonardo’s modernity—an early intuition of conservation principles—while revealing his impatience with pseudo-scientific promises that flourish when audiences prefer marvels to proofs.