Adverb
By which; -- used relatively.
By what; how; -- used interrogatively.
Source: Webster's dictionaryAll men can see these tactics whereby I conquer, but what none can see is the strategy out of which victory is evolved. Sun Tzu
Do not think about or do anything without a spiritual purpose, whereby it is done for God. For If you travel without purpose, you shall labor in vain. Marcus Eremita
Every happening, great and small, is a parable whereby God speaks to us, and the art of life is to get the message. Malcolm Muggeridge
There is ... but one categorical imperative Act only on that maxim whereby thou canst at the same time will that it should become a universal law. Immanuel Kant
By means of microscopic observation and astronomical projection the lotus flower can become the foundation for an entire theory of the universe and an agent whereby we may perceive Truth. Yukio Mishima
Roughly speaking, rationality is concerned with the selection of preferred behavior alternatives in terms of some system of values, whereby the consequences of behavior can be evaluated. Herbert Simon