Or shear swine, all cry and no wool. - Samuel Butler

They who study mathematiks only to fix their minds, and render them the steadyer to apply to all other things, as there are many who profess to do, are as wise as those who think by rowing boats, to learn to swim.

Some have been beaten till they know
What wood a cudgel's of by th' blow;
Some kick'd until they can feel whether
A shoe be Spanish or neat's leather.

There are more fools than knaves in the world, else the knaves would not have enough to live upon.