TOS #5: The Enemy Within

Yet another episode that I had not seen and therefore didn't realize was the basis of so many future Star Trek episodes...

Before Yeoman Rand's Mascara


After Yeoman Rand's Mascara


It is dangerous to separate the id from the ego. It is dangerous to pretend we are not part animal. To control the enemy within is not to ignore it or pretend it away.

"...his evil side, properly controlled and disciplined, is vital to his strength. Your negative side removed from you, the power of command begins to elude you."