κατανοητέον
From LSJ
ἁρμονίη ἀφανὴς φανερῆς κρείττων → the hidden attunement is better than the obvious one, invisible connection is stronger than visible, harmony we can't see is stronger than harmony we can, unseen harmony is stronger than what we can see
English (LSJ)
A one must observe, learn, Pl.Plt.305c, Porph.Marc.27; one must consider, πάλιν περί τινος Ph.1.83.
Greek (Liddell-Scott)
κατανοητέον: ῥημ. ἐπίθ., πρέπει νὰ μάθῃ τις, νὰ παρατηρήσῃ, Πλάτ. Πολιτ. 305C.
Dutch (Woordenboekgrieks.nl)
κατανοητέον, adj. verb. van κατανοέω, men moet beseffen.