And let it be remembered that to make this demand is in no way to violate the great rule of Aristotle, and to demand a greater accuracy than the nature of the subject will admit of.

The 'highest good,' it is quite possible, may be a vague thing; not capable, like a figure in Euclid, of being defined exactly.

But many vague things can be described exactly enough for all practical purposes.

They can be described so that we at once know what is meant, and so that we can at once find and recognise them.

Feelings, characters, and personal appearance are things of this sort; so too is the taste of food, the style of furniture, or the general tone and tenour of our life, under various circumstances.