Theory is the essence of ...

Theory is the essence of facts. Without theory scientific knowledge would be only worthy of the madhouse.
Theory is the essence of facts. Without theory scientific knowledge would be only worthy of the madhouse.
 Oliver Heaviside

More phrases

If one does not know to which port one is sailing, no wind is favorable.
What a distressing contrast there is between the radiant intelligence of the child and the feeble mentality of the average adult.
We are masters of the unsaid words, but slaves of those we let slip out.
I have always found that mercy bears richer fruits than strict justice.
A lie gets halfway around the world before the truth has a chance to get its pants on.

Quotes from the same author

The best result of mathematics is to be able to do without it.
 Oliver Heaviside
...there is no absolute scale of size in nature, and the small may be as important, or more so than the great.
 Oliver Heaviside
Electric and magnetic forces. May they live for ever, and never be forgot, if only to remind us that the science of electromagnetics, in spite of the abstract nature of its theory, involving quantities whose nature is entirely unknown at the present, is really and truly founded on the observations of real Newtonian forces, electric and magnetic respectively.
 Oliver Heaviside
However absurd it may seem, I do in all seriousness hereby declare that I am animated mainly by philanthropic motives. I desire to do good to my fellow creatures, even to the Cui bonos.
 Oliver Heaviside
Mathematics is an experimental science, and definitions do not come first, but later on.
 Oliver Heaviside