In the strict scientific sense we all feed on death -

Related:

• As we know, the value of pi is a transcendental figure without resolution.
  Spock, "Wolf in the Fold," stardate 3615.4...
• Anger is a relative state. -- Spock,
  "Wolf in the Fold," stardate 3615.4...
• Women are more easily and more deeply terrified ...
  generating more sheer horror than the male of the species...
• Deriving sustenance from emotion is not unknown in the galaxy.
  And fear is among the strongest and most violent...
• Jealousy has often been a motive for murder. -- Kirk,
  "Wolf in the Fold," stardate 3614.9...
• Kirk: "We have a problem. Something may be wrong on Regula One,
  we've been ordered to investigate." Spock: "If memory...
• Kirk: "Gentlemen, I must get you to reconsider. We can be of immense help to you.
  In addition to military aid, we can send you specialists...
• If there are self-made purgatories, then we all have to live in them.
  Spock, "This Side of Paradise," stardate 3417.7...
• Kirk: "Well, at least we have them all together." Spock:
  "Fortuitous, Captain." -- "Catspaw", Stardate 3018...