We know more about the movement of celestial bodies than about the soil underfoot.

The line contrasts humanity’s fascination with distant, spectacular phenomena (the heavens) with neglect of the immediate, practical world (the ground beneath us). Read as a critique of misplaced intellectual priorities, it suggests that everyday systems—soil, earth processes, agriculture, and the material conditions of life—remain poorly understood even while people pursue lofty cosmological knowledge. In a modern register, it anticipates later observations about scientific attention skewing toward the dramatic or prestigious rather than the foundational. Attributed to Leonardo, it also fits his broader habit of urging direct observation of nature and valuing empirical study of ordinary physical processes.