The second is derived from the three kinds of pleasure, which answer to the three elements of the soul--reason, passion, desire; under which last is comprehended avarice as well as sensual appetite, while passion includes ambition, party-feeling, love of reputation.

Reason, again, is solely directed to the attainment of truth, and careless of money and reputation.

In accordance with the difference of men's natures, one of these three principles is in the ascendant, and they have their several pleasures corresponding to them.
Interrogate now the three natures, and each one will be found praising his own pleasures and depreciating those of others.

The money-maker will contrast the vanity of knowledge with the solid advantages of wealth.
The ambitious man will despise knowledge which brings no honour; whereas the philosopher will regard only the fruition of truth, and will call other pleasures necessary rather than good.

Now, how shall we decide between them?
Is there any better criterion than experience and knowledge?
And which of the three has the truest knowledge and the widest experience?
The experience of youth makes the philosopher acquainted with the two kinds of desire, but the avaricious and the ambitious man never taste the pleasures of truth and wisdom.