All we know is still infinitely less than all that still remains unknown.

The line expresses an epistemic humility often associated with early modern scientific inquiry: however much humans discover, the unknown will always dwarf the known. Read in relation to Harvey’s experimental approach to anatomy and physiology, it underscores a commitment to observation and revision rather than final certainty. The quote also functions as a caution against intellectual complacency—progress in knowledge should expand curiosity, not close it. More broadly, it frames learning as asymptotic: each answer reveals further questions, making ignorance not a defect to be eliminated but a horizon that continually recedes as understanding grows.