Watson, a steam engine without a safety valve is merely a bomb. Limits preserve the machinery of life.
Do not step into the fog before checking your lantern, Watson. Early restraint prevents fatal missteps.
Watson, hesitating when the carriage door is open is not caution; it is cowardice. The culprit has escaped.
If you overfill the beaker, Watson, do not complain when the acid ruins your trousers. Know your capacity.
The most efficient pocket watch ticks without friction, Watson. Silent self-regulation is the key to endurance.
Lead by example, Watson. A moderate dose of digitalis stabilizes the heart; excess kills.
A spring wound too tightly will snap, Watson. Tyrannical rules invite inevitable ruin.