You must drain it to the end if you are to find those drops of divine sweetness you seem so much to thirst for! Yourself, after drinking so deeply, are still but at the beginning, as you said.

But is not philosophy rather like this?
Keep the figure of the merchant and the cask: but let it be filled, not with wine, but with every sort of grain.

You come to buy.

The merchant hands you a little of the wheat which lies at the top.

Could you tell by looking at that, whether the chick-peas were clean, the lentils tender, the beans full?
And then, whereas in selecting our wine we risk only our money; in selecting our philosophy we risk ourselves, as you told me--might ourselves sink into the dregs of 'the vulgar herd.' Moreover, while you may not drain the whole cask of wine by way of tasting, Wisdom grows no less by the depth of your drinking.