When a person cannot deceive ...

When a person cannot deceive himself the chances are against his being able to deceive other people.
When a person cannot deceive himself the chances are against his being able to deceive other people.

Quotes from the same author

Whenever you find yourself on the side of the majority, it is time to pause and reflect.
Wrinkles should merely indicate where smiles have been.
Whoever is happy will make others happy, too.
Always tell the truth. That way, you don't have to remember what you said.
A thing long expected takes the form of the unexpected when at last it comes.