一以贯之 Origin — Chinese Character Wiki

yīyǐguànzhī

to be consistent throughout

一 yī numeral

same

same; identical; unified
以 yǐ preposition

by means of

to use; by means of; with; using the tool or method introduced
贯貫 guàn verb

to pierce

to pierce through; to pass through
之 zhī pronoun

it

Used only in the object position to refer to a person or thing already mentioned, meaning "him", "her", "it", or "them".