From Plato's Philebus

Soc. Would you care, Protarchus, to live your whole life in theenjoyment of the greatest pleasures?

Prot. Certainly.

Soc. Then you wouldn't think you needed anything else, if you had that in the fullest measure?

Prot. I'm sure I shouldn't.

Soc. Now be careful, are you sure you wouldn't need anything inthe way of thought, intelligence, calculating what is fitting, and so on?

Prot. Why should I? If I had my enjoyment what more could Iwant?

Soc. Then if you lived your whole life long like that you wouldbe enjoying the greatest pleasures, would you?

Prot. Of course..

Soc. But if you were without memory, reason, knowledge, and truejudgment, you would necessarily, I imagine, in the first place beunaware even whether you were, or were not, enjoying yourself, asyou would be destitute of all intelligence.

Prot. Necessarily.

Soc. And surely again, if you had no memory you wouldnecessarily, I imagine, not even remember that you had beenenjoying yourself; of the pleasure you encountered at one momentnot a vestige of memory would be left at the next. Once more, ifyou had no true judgment you couldn't judge that you wereenjoying yourself when you were; if you were bereft of the powerof calculation you couldn't even calculate that you could enjoyyourself later on; you would be living the life not of a humanbeing butof some sort of sea-lung or one of those creatures ofthe ocean whose bodies are encased in shells. Am I right, or canwe imagine the situation to be otherwise?

Prot. We cannot.

Soc. Then is a life like that one we can desire?

Prot. Your argument, Socrates, has reduced me for the moment tocomplete speechlessness.