Thoughts on the True Estimation of Living Forces (German: Gedanken von der wahren Schätzung der lebendigen Kräfte) is Immanuel Kant's first published work, published in 1749.

[1] Although written in 1744–46 when Kant was a young student, it was published in 1749 (not 1747, as is often claimed) since publication was delayed for three years due to financial issues.

[2] Kant’s aim in the True Estimation was to settle the vis viva debate amongst Descartes and Leibniz as well as their respective followers.

[3] It reflected Kant's position as a metaphysical dualist at the time.

Kant criticized Leibniz's followers for looking "no further than the senses teach," and stayed close to Leibniz's original vis activa ("active force"; also known as vis viva, "living force") point of view.