οὐ διχορρόπως
From LSJ
ἐν πίθῳ τὴν κεραμείαν μανθάνειν → in breaking many pots, the potter learns his craft | of those who undertake the most difficult tasks without learning the elements of the art | don't run before you can walk
Greek > English (Woodhouse)
indisputably, beyond dispute, not doubtfully, without doubt
Russian (Dvoretsky)
μὴ διχορρόπως Aesch. без колебаний, твердо.